Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * parse_target.c
4 : * handle target lists
5 : *
6 : * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/backend/parser/parse_target.c
12 : *
13 : *-------------------------------------------------------------------------
14 : */
15 : #include "postgres.h"
16 :
17 : #include "catalog/pg_type.h"
18 : #include "commands/dbcommands.h"
19 : #include "funcapi.h"
20 : #include "miscadmin.h"
21 : #include "nodes/makefuncs.h"
22 : #include "nodes/nodeFuncs.h"
23 : #include "parser/parsetree.h"
24 : #include "parser/parse_coerce.h"
25 : #include "parser/parse_expr.h"
26 : #include "parser/parse_func.h"
27 : #include "parser/parse_relation.h"
28 : #include "parser/parse_target.h"
29 : #include "parser/parse_type.h"
30 : #include "utils/builtins.h"
31 : #include "utils/lsyscache.h"
32 : #include "utils/rel.h"
33 : #include "utils/typcache.h"
34 :
35 :
36 : static void markTargetListOrigin(ParseState *pstate, TargetEntry *tle,
37 : Var *var, int levelsup);
38 : static Node *transformAssignmentIndirection(ParseState *pstate,
39 : Node *basenode,
40 : const char *targetName,
41 : bool targetIsArray,
42 : Oid targetTypeId,
43 : int32 targetTypMod,
44 : Oid targetCollation,
45 : ListCell *indirection,
46 : Node *rhs,
47 : int location);
48 : static Node *transformAssignmentSubscripts(ParseState *pstate,
49 : Node *basenode,
50 : const char *targetName,
51 : Oid targetTypeId,
52 : int32 targetTypMod,
53 : Oid targetCollation,
54 : List *subscripts,
55 : bool isSlice,
56 : ListCell *next_indirection,
57 : Node *rhs,
58 : int location);
59 : static List *ExpandColumnRefStar(ParseState *pstate, ColumnRef *cref,
60 : bool make_target_entry);
61 : static List *ExpandAllTables(ParseState *pstate, int location);
62 : static List *ExpandIndirectionStar(ParseState *pstate, A_Indirection *ind,
63 : bool make_target_entry, ParseExprKind exprKind);
64 : static List *ExpandSingleTable(ParseState *pstate, RangeTblEntry *rte,
65 : int location, bool make_target_entry);
66 : static List *ExpandRowReference(ParseState *pstate, Node *expr,
67 : bool make_target_entry);
68 : static int FigureColnameInternal(Node *node, char **name);
69 :
70 :
71 : /*
72 : * transformTargetEntry()
73 : * Transform any ordinary "expression-type" node into a targetlist entry.
74 : * This is exported so that parse_clause.c can generate targetlist entries
75 : * for ORDER/GROUP BY items that are not already in the targetlist.
76 : *
77 : * node the (untransformed) parse tree for the value expression.
78 : * expr the transformed expression, or NULL if caller didn't do it yet.
79 : * exprKind expression kind (EXPR_KIND_SELECT_TARGET, etc)
80 : * colname the column name to be assigned, or NULL if none yet set.
81 : * resjunk true if the target should be marked resjunk, ie, it is not
82 : * wanted in the final projected tuple.
83 : */
84 : TargetEntry *
85 38013 : transformTargetEntry(ParseState *pstate,
86 : Node *node,
87 : Node *expr,
88 : ParseExprKind exprKind,
89 : char *colname,
90 : bool resjunk)
91 : {
92 : /* Transform the node if caller didn't do it already */
93 38013 : if (expr == NULL)
94 : {
95 : /*
96 : * If it's a SetToDefault node and we should allow that, pass it
97 : * through unmodified. (transformExpr will throw the appropriate
98 : * error if we're disallowing it.)
99 : */
100 37203 : if (exprKind == EXPR_KIND_UPDATE_SOURCE && IsA(node, SetToDefault))
101 18 : expr = node;
102 : else
103 37185 : expr = transformExpr(pstate, node, exprKind);
104 : }
105 :
106 37586 : if (colname == NULL && !resjunk)
107 : {
108 : /*
109 : * Generate a suitable column name for a column without any explicit
110 : * 'AS ColumnName' clause.
111 : */
112 30386 : colname = FigureColname(node);
113 : }
114 :
115 75172 : return makeTargetEntry((Expr *) expr,
116 37586 : (AttrNumber) pstate->p_next_resno++,
117 : colname,
118 : resjunk);
119 : }
120 :
121 :
122 : /*
123 : * transformTargetList()
124 : * Turns a list of ResTarget's into a list of TargetEntry's.
125 : *
126 : * This code acts mostly the same for SELECT, UPDATE, or RETURNING lists;
127 : * the main thing is to transform the given expressions (the "val" fields).
128 : * The exprKind parameter distinguishes these cases when necessary.
129 : */
130 : List *
131 25473 : transformTargetList(ParseState *pstate, List *targetlist,
132 : ParseExprKind exprKind)
133 : {
134 25473 : List *p_target = NIL;
135 : bool expand_star;
136 : ListCell *o_target;
137 :
138 : /* Shouldn't have any leftover multiassign items at start */
139 25473 : Assert(pstate->p_multiassign_exprs == NIL);
140 :
141 : /* Expand "something.*" in SELECT and RETURNING, but not UPDATE */
142 25473 : expand_star = (exprKind != EXPR_KIND_UPDATE_SOURCE);
143 :
144 65599 : foreach(o_target, targetlist)
145 : {
146 40554 : ResTarget *res = (ResTarget *) lfirst(o_target);
147 :
148 : /*
149 : * Check for "something.*". Depending on the complexity of the
150 : * "something", the star could appear as the last field in ColumnRef,
151 : * or as the last indirection item in A_Indirection.
152 : */
153 40554 : if (expand_star)
154 : {
155 39752 : if (IsA(res->val, ColumnRef))
156 : {
157 16160 : ColumnRef *cref = (ColumnRef *) res->val;
158 :
159 16160 : if (IsA(llast(cref->fields), A_Star))
160 : {
161 : /* It is something.*, expand into multiple items */
162 3329 : p_target = list_concat(p_target,
163 : ExpandColumnRefStar(pstate,
164 : cref,
165 : true));
166 3328 : continue;
167 : }
168 : }
169 23592 : else if (IsA(res->val, A_Indirection))
170 : {
171 169 : A_Indirection *ind = (A_Indirection *) res->val;
172 :
173 169 : if (IsA(llast(ind->indirection), A_Star))
174 : {
175 : /* It is something.*, expand into multiple items */
176 22 : p_target = list_concat(p_target,
177 : ExpandIndirectionStar(pstate,
178 : ind,
179 : true,
180 : exprKind));
181 22 : continue;
182 : }
183 : }
184 : }
185 :
186 : /*
187 : * Not "something.*", or we want to treat that as a plain whole-row
188 : * variable, so transform as a single expression
189 : */
190 36776 : p_target = lappend(p_target,
191 37203 : transformTargetEntry(pstate,
192 : res->val,
193 : NULL,
194 : exprKind,
195 : res->name,
196 : false));
197 : }
198 :
199 : /*
200 : * If any multiassign resjunk items were created, attach them to the end
201 : * of the targetlist. This should only happen in an UPDATE tlist. We
202 : * don't need to worry about numbering of these items; transformUpdateStmt
203 : * will set their resnos.
204 : */
205 25045 : if (pstate->p_multiassign_exprs)
206 : {
207 9 : Assert(exprKind == EXPR_KIND_UPDATE_SOURCE);
208 9 : p_target = list_concat(p_target, pstate->p_multiassign_exprs);
209 9 : pstate->p_multiassign_exprs = NIL;
210 : }
211 :
212 25045 : return p_target;
213 : }
214 :
215 :
216 : /*
217 : * transformExpressionList()
218 : *
219 : * This is the identical transformation to transformTargetList, except that
220 : * the input list elements are bare expressions without ResTarget decoration,
221 : * and the output elements are likewise just expressions without TargetEntry
222 : * decoration. We use this for ROW() and VALUES() constructs.
223 : *
224 : * exprKind is not enough to tell us whether to allow SetToDefault, so
225 : * an additional flag is needed for that.
226 : */
227 : List *
228 5374 : transformExpressionList(ParseState *pstate, List *exprlist,
229 : ParseExprKind exprKind, bool allowDefault)
230 : {
231 5374 : List *result = NIL;
232 : ListCell *lc;
233 :
234 16354 : foreach(lc, exprlist)
235 : {
236 10989 : Node *e = (Node *) lfirst(lc);
237 :
238 : /*
239 : * Check for "something.*". Depending on the complexity of the
240 : * "something", the star could appear as the last field in ColumnRef,
241 : * or as the last indirection item in A_Indirection.
242 : */
243 10989 : if (IsA(e, ColumnRef))
244 : {
245 232 : ColumnRef *cref = (ColumnRef *) e;
246 :
247 232 : if (IsA(llast(cref->fields), A_Star))
248 : {
249 : /* It is something.*, expand into multiple items */
250 34 : result = list_concat(result,
251 : ExpandColumnRefStar(pstate, cref,
252 : false));
253 34 : continue;
254 : }
255 : }
256 10757 : else if (IsA(e, A_Indirection))
257 : {
258 4 : A_Indirection *ind = (A_Indirection *) e;
259 :
260 4 : if (IsA(llast(ind->indirection), A_Star))
261 : {
262 : /* It is something.*, expand into multiple items */
263 0 : result = list_concat(result,
264 : ExpandIndirectionStar(pstate, ind,
265 : false, exprKind));
266 0 : continue;
267 : }
268 : }
269 :
270 : /*
271 : * Not "something.*", so transform as a single expression. If it's a
272 : * SetToDefault node and we should allow that, pass it through
273 : * unmodified. (transformExpr will throw the appropriate error if
274 : * we're disallowing it.)
275 : */
276 10955 : if (allowDefault && IsA(e, SetToDefault))
277 : /* do nothing */ ;
278 : else
279 10933 : e = transformExpr(pstate, e, exprKind);
280 :
281 10946 : result = lappend(result, e);
282 : }
283 :
284 : /* Shouldn't have any multiassign items here */
285 5365 : Assert(pstate->p_multiassign_exprs == NIL);
286 :
287 5365 : return result;
288 : }
289 :
290 :
291 : /*
292 : * resolveTargetListUnknowns()
293 : * Convert any unknown-type targetlist entries to type TEXT.
294 : *
295 : * We do this after we've exhausted all other ways of identifying the output
296 : * column types of a query.
297 : */
298 : void
299 23178 : resolveTargetListUnknowns(ParseState *pstate, List *targetlist)
300 : {
301 : ListCell *l;
302 :
303 68492 : foreach(l, targetlist)
304 : {
305 45314 : TargetEntry *tle = (TargetEntry *) lfirst(l);
306 45314 : Oid restype = exprType((Node *) tle->expr);
307 :
308 45314 : if (restype == UNKNOWNOID)
309 : {
310 1278 : tle->expr = (Expr *) coerce_type(pstate, (Node *) tle->expr,
311 : restype, TEXTOID, -1,
312 : COERCION_IMPLICIT,
313 : COERCE_IMPLICIT_CAST,
314 : -1);
315 : }
316 : }
317 23178 : }
318 :
319 :
320 : /*
321 : * markTargetListOrigins()
322 : * Mark targetlist columns that are simple Vars with the source
323 : * table's OID and column number.
324 : *
325 : * Currently, this is done only for SELECT targetlists and RETURNING lists,
326 : * since we only need the info if we are going to send it to the frontend.
327 : */
328 : void
329 24376 : markTargetListOrigins(ParseState *pstate, List *targetlist)
330 : {
331 : ListCell *l;
332 :
333 71185 : foreach(l, targetlist)
334 : {
335 46809 : TargetEntry *tle = (TargetEntry *) lfirst(l);
336 :
337 46809 : markTargetListOrigin(pstate, tle, (Var *) tle->expr, 0);
338 : }
339 24376 : }
340 :
341 : /*
342 : * markTargetListOrigin()
343 : * If 'var' is a Var of a plain relation, mark 'tle' with its origin
344 : *
345 : * levelsup is an extra offset to interpret the Var's varlevelsup correctly.
346 : *
347 : * This is split out so it can recurse for join references. Note that we
348 : * do not drill down into views, but report the view as the column owner.
349 : */
350 : static void
351 48570 : markTargetListOrigin(ParseState *pstate, TargetEntry *tle,
352 : Var *var, int levelsup)
353 : {
354 : int netlevelsup;
355 : RangeTblEntry *rte;
356 : AttrNumber attnum;
357 :
358 48570 : if (var == NULL || !IsA(var, Var))
359 72377 : return;
360 24763 : netlevelsup = var->varlevelsup + levelsup;
361 24763 : rte = GetRTEByRangeTablePosn(pstate, var->varno, netlevelsup);
362 24763 : attnum = var->varattno;
363 :
364 24763 : switch (rte->rtekind)
365 : {
366 : case RTE_RELATION:
367 : /* It's a table or view, report it */
368 20385 : tle->resorigtbl = rte->relid;
369 20385 : tle->resorigcol = attnum;
370 20385 : break;
371 : case RTE_SUBQUERY:
372 : /* Subselect-in-FROM: copy up from the subselect */
373 733 : if (attnum != InvalidAttrNumber)
374 : {
375 726 : TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
376 : attnum);
377 :
378 726 : if (ste == NULL || ste->resjunk)
379 0 : elog(ERROR, "subquery %s does not have attribute %d",
380 : rte->eref->aliasname, attnum);
381 726 : tle->resorigtbl = ste->resorigtbl;
382 726 : tle->resorigcol = ste->resorigcol;
383 : }
384 733 : break;
385 : case RTE_JOIN:
386 : /* Join RTE --- recursively inspect the alias variable */
387 1761 : if (attnum != InvalidAttrNumber)
388 : {
389 : Var *aliasvar;
390 :
391 1761 : Assert(attnum > 0 && attnum <= list_length(rte->joinaliasvars));
392 1761 : aliasvar = (Var *) list_nth(rte->joinaliasvars, attnum - 1);
393 : /* We intentionally don't strip implicit coercions here */
394 1761 : markTargetListOrigin(pstate, tle, aliasvar, netlevelsup);
395 : }
396 1761 : break;
397 : case RTE_FUNCTION:
398 : case RTE_VALUES:
399 : case RTE_TABLEFUNC:
400 : case RTE_NAMEDTUPLESTORE:
401 : /* not a simple relation, leave it unmarked */
402 1660 : break;
403 : case RTE_CTE:
404 :
405 : /*
406 : * CTE reference: copy up from the subquery, if possible. If the
407 : * RTE is a recursive self-reference then we can't do anything
408 : * because we haven't finished analyzing it yet. However, it's no
409 : * big loss because we must be down inside the recursive term of a
410 : * recursive CTE, and so any markings on the current targetlist
411 : * are not going to affect the results anyway.
412 : */
413 224 : if (attnum != InvalidAttrNumber && !rte->self_reference)
414 : {
415 207 : CommonTableExpr *cte = GetCTEForRTE(pstate, rte, netlevelsup);
416 : TargetEntry *ste;
417 :
418 207 : ste = get_tle_by_resno(GetCTETargetList(cte), attnum);
419 207 : if (ste == NULL || ste->resjunk)
420 0 : elog(ERROR, "subquery %s does not have attribute %d",
421 : rte->eref->aliasname, attnum);
422 207 : tle->resorigtbl = ste->resorigtbl;
423 207 : tle->resorigcol = ste->resorigcol;
424 : }
425 224 : break;
426 : }
427 : }
428 :
429 :
430 : /*
431 : * transformAssignedExpr()
432 : * This is used in INSERT and UPDATE statements only. It prepares an
433 : * expression for assignment to a column of the target table.
434 : * This includes coercing the given value to the target column's type
435 : * (if necessary), and dealing with any subfield names or subscripts
436 : * attached to the target column itself. The input expression has
437 : * already been through transformExpr().
438 : *
439 : * pstate parse state
440 : * expr expression to be modified
441 : * exprKind indicates which type of statement we're dealing with
442 : * colname target column name (ie, name of attribute to be assigned to)
443 : * attrno target attribute number
444 : * indirection subscripts/field names for target column, if any
445 : * location error cursor position for the target column, or -1
446 : *
447 : * Returns the modified expression.
448 : *
449 : * Note: location points at the target column name (SET target or INSERT
450 : * column name list entry), and must therefore be -1 in an INSERT that
451 : * omits the column name list. So we should usually prefer to use
452 : * exprLocation(expr) for errors that can happen in a default INSERT.
453 : */
454 : Expr *
455 9767 : transformAssignedExpr(ParseState *pstate,
456 : Expr *expr,
457 : ParseExprKind exprKind,
458 : char *colname,
459 : int attrno,
460 : List *indirection,
461 : int location)
462 : {
463 9767 : Relation rd = pstate->p_target_relation;
464 : Oid type_id; /* type of value provided */
465 : Oid attrtype; /* type of target column */
466 : int32 attrtypmod;
467 : Oid attrcollation; /* collation of target column */
468 : ParseExprKind sv_expr_kind;
469 :
470 : /*
471 : * Save and restore identity of expression type we're parsing. We must
472 : * set p_expr_kind here because we can parse subscripts without going
473 : * through transformExpr().
474 : */
475 9767 : Assert(exprKind != EXPR_KIND_NONE);
476 9767 : sv_expr_kind = pstate->p_expr_kind;
477 9767 : pstate->p_expr_kind = exprKind;
478 :
479 9767 : Assert(rd != NULL);
480 9767 : if (attrno <= 0)
481 0 : ereport(ERROR,
482 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
483 : errmsg("cannot assign to system column \"%s\"",
484 : colname),
485 : parser_errposition(pstate, location)));
486 9767 : attrtype = attnumTypeId(rd, attrno);
487 9767 : attrtypmod = TupleDescAttr(rd->rd_att, attrno - 1)->atttypmod;
488 9767 : attrcollation = TupleDescAttr(rd->rd_att, attrno - 1)->attcollation;
489 :
490 : /*
491 : * If the expression is a DEFAULT placeholder, insert the attribute's
492 : * type/typmod/collation into it so that exprType etc will report the
493 : * right things. (We expect that the eventually substituted default
494 : * expression will in fact have this type and typmod. The collation
495 : * likely doesn't matter, but let's set it correctly anyway.) Also,
496 : * reject trying to update a subfield or array element with DEFAULT, since
497 : * there can't be any default for portions of a column.
498 : */
499 9767 : if (expr && IsA(expr, SetToDefault))
500 : {
501 35 : SetToDefault *def = (SetToDefault *) expr;
502 :
503 35 : def->typeId = attrtype;
504 35 : def->typeMod = attrtypmod;
505 35 : def->collation = attrcollation;
506 35 : if (indirection)
507 : {
508 2 : if (IsA(linitial(indirection), A_Indices))
509 1 : ereport(ERROR,
510 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
511 : errmsg("cannot set an array element to DEFAULT"),
512 : parser_errposition(pstate, location)));
513 : else
514 1 : ereport(ERROR,
515 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
516 : errmsg("cannot set a subfield to DEFAULT"),
517 : parser_errposition(pstate, location)));
518 : }
519 : }
520 :
521 : /* Now we can use exprType() safely. */
522 9765 : type_id = exprType((Node *) expr);
523 :
524 : /*
525 : * If there is indirection on the target column, prepare an array or
526 : * subfield assignment expression. This will generate a new column value
527 : * that the source value has been inserted into, which can then be placed
528 : * in the new tuple constructed by INSERT or UPDATE.
529 : */
530 9765 : if (indirection)
531 : {
532 : Node *colVar;
533 :
534 143 : if (pstate->p_is_insert)
535 : {
536 : /*
537 : * The command is INSERT INTO table (col.something) ... so there
538 : * is not really a source value to work with. Insert a NULL
539 : * constant as the source value.
540 : */
541 71 : colVar = (Node *) makeNullConst(attrtype, attrtypmod,
542 : attrcollation);
543 : }
544 : else
545 : {
546 : /*
547 : * Build a Var for the column to be updated.
548 : */
549 72 : colVar = (Node *) make_var(pstate,
550 : pstate->p_target_rangetblentry,
551 : attrno,
552 : location);
553 : }
554 :
555 143 : expr = (Expr *)
556 143 : transformAssignmentIndirection(pstate,
557 : colVar,
558 : colname,
559 : false,
560 : attrtype,
561 : attrtypmod,
562 : attrcollation,
563 : list_head(indirection),
564 : (Node *) expr,
565 : location);
566 : }
567 : else
568 : {
569 : /*
570 : * For normal non-qualified target column, do type checking and
571 : * coercion.
572 : */
573 9622 : Node *orig_expr = (Node *) expr;
574 :
575 9622 : expr = (Expr *)
576 : coerce_to_target_type(pstate,
577 : orig_expr, type_id,
578 : attrtype, attrtypmod,
579 : COERCION_ASSIGNMENT,
580 : COERCE_IMPLICIT_CAST,
581 : -1);
582 9476 : if (expr == NULL)
583 2 : ereport(ERROR,
584 : (errcode(ERRCODE_DATATYPE_MISMATCH),
585 : errmsg("column \"%s\" is of type %s"
586 : " but expression is of type %s",
587 : colname,
588 : format_type_be(attrtype),
589 : format_type_be(type_id)),
590 : errhint("You will need to rewrite or cast the expression."),
591 : parser_errposition(pstate, exprLocation(orig_expr))));
592 : }
593 :
594 9617 : pstate->p_expr_kind = sv_expr_kind;
595 :
596 9617 : return expr;
597 : }
598 :
599 :
600 : /*
601 : * updateTargetListEntry()
602 : * This is used in UPDATE statements (and ON CONFLICT DO UPDATE)
603 : * only. It prepares an UPDATE TargetEntry for assignment to a
604 : * column of the target table. This includes coercing the given
605 : * value to the target column's type (if necessary), and dealing with
606 : * any subfield names or subscripts attached to the target column
607 : * itself.
608 : *
609 : * pstate parse state
610 : * tle target list entry to be modified
611 : * colname target column name (ie, name of attribute to be assigned to)
612 : * attrno target attribute number
613 : * indirection subscripts/field names for target column, if any
614 : * location error cursor position (should point at column name), or -1
615 : */
616 : void
617 792 : updateTargetListEntry(ParseState *pstate,
618 : TargetEntry *tle,
619 : char *colname,
620 : int attrno,
621 : List *indirection,
622 : int location)
623 : {
624 : /* Fix up expression as needed */
625 792 : tle->expr = transformAssignedExpr(pstate,
626 : tle->expr,
627 : EXPR_KIND_UPDATE_TARGET,
628 : colname,
629 : attrno,
630 : indirection,
631 : location);
632 :
633 : /*
634 : * Set the resno to identify the target column --- the rewriter and
635 : * planner depend on this. We also set the resname to identify the target
636 : * column, but this is only for debugging purposes; it should not be
637 : * relied on. (In particular, it might be out of date in a stored rule.)
638 : */
639 791 : tle->resno = (AttrNumber) attrno;
640 791 : tle->resname = colname;
641 791 : }
642 :
643 :
644 : /*
645 : * Process indirection (field selection or subscripting) of the target
646 : * column in INSERT/UPDATE. This routine recurses for multiple levels
647 : * of indirection --- but note that several adjacent A_Indices nodes in
648 : * the indirection list are treated as a single multidimensional subscript
649 : * operation.
650 : *
651 : * In the initial call, basenode is a Var for the target column in UPDATE,
652 : * or a null Const of the target's type in INSERT. In recursive calls,
653 : * basenode is NULL, indicating that a substitute node should be consed up if
654 : * needed.
655 : *
656 : * targetName is the name of the field or subfield we're assigning to, and
657 : * targetIsArray is true if we're subscripting it. These are just for
658 : * error reporting.
659 : *
660 : * targetTypeId, targetTypMod, targetCollation indicate the datatype and
661 : * collation of the object to be assigned to (initially the target column,
662 : * later some subobject).
663 : *
664 : * indirection is the sublist remaining to process. When it's NULL, we're
665 : * done recursing and can just coerce and return the RHS.
666 : *
667 : * rhs is the already-transformed value to be assigned; note it has not been
668 : * coerced to any particular type.
669 : *
670 : * location is the cursor error position for any errors. (Note: this points
671 : * to the head of the target clause, eg "foo" in "foo.bar[baz]". Later we
672 : * might want to decorate indirection cells with their own location info,
673 : * in which case the location argument could probably be dropped.)
674 : */
675 : static Node *
676 348 : transformAssignmentIndirection(ParseState *pstate,
677 : Node *basenode,
678 : const char *targetName,
679 : bool targetIsArray,
680 : Oid targetTypeId,
681 : int32 targetTypMod,
682 : Oid targetCollation,
683 : ListCell *indirection,
684 : Node *rhs,
685 : int location)
686 : {
687 : Node *result;
688 348 : List *subscripts = NIL;
689 348 : bool isSlice = false;
690 : ListCell *i;
691 :
692 348 : if (indirection && !basenode)
693 : {
694 : /* Set up a substitution. We reuse CaseTestExpr for this. */
695 62 : CaseTestExpr *ctest = makeNode(CaseTestExpr);
696 :
697 62 : ctest->typeId = targetTypeId;
698 62 : ctest->typeMod = targetTypMod;
699 62 : ctest->collation = targetCollation;
700 62 : basenode = (Node *) ctest;
701 : }
702 :
703 : /*
704 : * We have to split any field-selection operations apart from
705 : * subscripting. Adjacent A_Indices nodes have to be treated as a single
706 : * multidimensional subscript operation.
707 : */
708 500 : for_each_cell(i, indirection)
709 : {
710 248 : Node *n = lfirst(i);
711 :
712 248 : if (IsA(n, A_Indices))
713 : {
714 152 : subscripts = lappend(subscripts, n);
715 152 : if (((A_Indices *) n)->is_slice)
716 44 : isSlice = true;
717 : }
718 96 : else if (IsA(n, A_Star))
719 : {
720 0 : ereport(ERROR,
721 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
722 : errmsg("row expansion via \"*\" is not supported here"),
723 : parser_errposition(pstate, location)));
724 : }
725 : else
726 : {
727 : FieldStore *fstore;
728 : Oid typrelid;
729 : AttrNumber attnum;
730 : Oid fieldTypeId;
731 : int32 fieldTypMod;
732 : Oid fieldCollation;
733 :
734 96 : Assert(IsA(n, String));
735 :
736 : /* process subscripts before this field selection */
737 96 : if (subscripts)
738 : {
739 : /* recurse, and then return because we're done */
740 34 : return transformAssignmentSubscripts(pstate,
741 : basenode,
742 : targetName,
743 : targetTypeId,
744 : targetTypMod,
745 : targetCollation,
746 : subscripts,
747 : isSlice,
748 : i,
749 : rhs,
750 : location);
751 : }
752 :
753 : /* No subscripts, so can process field selection here */
754 :
755 62 : typrelid = typeidTypeRelid(targetTypeId);
756 62 : if (!typrelid)
757 0 : ereport(ERROR,
758 : (errcode(ERRCODE_DATATYPE_MISMATCH),
759 : errmsg("cannot assign to field \"%s\" of column \"%s\" because its type %s is not a composite type",
760 : strVal(n), targetName,
761 : format_type_be(targetTypeId)),
762 : parser_errposition(pstate, location)));
763 :
764 62 : attnum = get_attnum(typrelid, strVal(n));
765 62 : if (attnum == InvalidAttrNumber)
766 0 : ereport(ERROR,
767 : (errcode(ERRCODE_UNDEFINED_COLUMN),
768 : errmsg("cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
769 : strVal(n), targetName,
770 : format_type_be(targetTypeId)),
771 : parser_errposition(pstate, location)));
772 62 : if (attnum < 0)
773 0 : ereport(ERROR,
774 : (errcode(ERRCODE_UNDEFINED_COLUMN),
775 : errmsg("cannot assign to system column \"%s\"",
776 : strVal(n)),
777 : parser_errposition(pstate, location)));
778 :
779 62 : get_atttypetypmodcoll(typrelid, attnum,
780 : &fieldTypeId, &fieldTypMod, &fieldCollation);
781 :
782 : /* recurse to create appropriate RHS for field assign */
783 124 : rhs = transformAssignmentIndirection(pstate,
784 : NULL,
785 62 : strVal(n),
786 : false,
787 : fieldTypeId,
788 : fieldTypMod,
789 : fieldCollation,
790 : lnext(i),
791 : rhs,
792 : location);
793 :
794 : /* and build a FieldStore node */
795 62 : fstore = makeNode(FieldStore);
796 62 : fstore->arg = (Expr *) basenode;
797 62 : fstore->newvals = list_make1(rhs);
798 62 : fstore->fieldnums = list_make1_int(attnum);
799 62 : fstore->resulttype = targetTypeId;
800 :
801 62 : return (Node *) fstore;
802 : }
803 : }
804 :
805 : /* process trailing subscripts, if any */
806 252 : if (subscripts)
807 : {
808 : /* recurse, and then return because we're done */
809 109 : return transformAssignmentSubscripts(pstate,
810 : basenode,
811 : targetName,
812 : targetTypeId,
813 : targetTypMod,
814 : targetCollation,
815 : subscripts,
816 : isSlice,
817 : NULL,
818 : rhs,
819 : location);
820 : }
821 :
822 : /* base case: just coerce RHS to match target type ID */
823 :
824 143 : result = coerce_to_target_type(pstate,
825 : rhs, exprType(rhs),
826 : targetTypeId, targetTypMod,
827 : COERCION_ASSIGNMENT,
828 : COERCE_IMPLICIT_CAST,
829 : -1);
830 143 : if (result == NULL)
831 : {
832 0 : if (targetIsArray)
833 0 : ereport(ERROR,
834 : (errcode(ERRCODE_DATATYPE_MISMATCH),
835 : errmsg("array assignment to \"%s\" requires type %s"
836 : " but expression is of type %s",
837 : targetName,
838 : format_type_be(targetTypeId),
839 : format_type_be(exprType(rhs))),
840 : errhint("You will need to rewrite or cast the expression."),
841 : parser_errposition(pstate, location)));
842 : else
843 0 : ereport(ERROR,
844 : (errcode(ERRCODE_DATATYPE_MISMATCH),
845 : errmsg("subfield \"%s\" is of type %s"
846 : " but expression is of type %s",
847 : targetName,
848 : format_type_be(targetTypeId),
849 : format_type_be(exprType(rhs))),
850 : errhint("You will need to rewrite or cast the expression."),
851 : parser_errposition(pstate, location)));
852 : }
853 :
854 143 : return result;
855 : }
856 :
857 : /*
858 : * helper for transformAssignmentIndirection: process array assignment
859 : */
860 : static Node *
861 143 : transformAssignmentSubscripts(ParseState *pstate,
862 : Node *basenode,
863 : const char *targetName,
864 : Oid targetTypeId,
865 : int32 targetTypMod,
866 : Oid targetCollation,
867 : List *subscripts,
868 : bool isSlice,
869 : ListCell *next_indirection,
870 : Node *rhs,
871 : int location)
872 : {
873 : Node *result;
874 : Oid arrayType;
875 : int32 arrayTypMod;
876 : Oid elementTypeId;
877 : Oid typeNeeded;
878 : Oid collationNeeded;
879 :
880 143 : Assert(subscripts != NIL);
881 :
882 : /* Identify the actual array type and element type involved */
883 143 : arrayType = targetTypeId;
884 143 : arrayTypMod = targetTypMod;
885 143 : elementTypeId = transformArrayType(&arrayType, &arrayTypMod);
886 :
887 : /* Identify type that RHS must provide */
888 143 : typeNeeded = isSlice ? arrayType : elementTypeId;
889 :
890 : /*
891 : * Array normally has same collation as elements, but there's an
892 : * exception: we might be subscripting a domain over an array type. In
893 : * that case use collation of the base type.
894 : */
895 143 : if (arrayType == targetTypeId)
896 121 : collationNeeded = targetCollation;
897 : else
898 22 : collationNeeded = get_typcollation(arrayType);
899 :
900 : /* recurse to create appropriate RHS for array assign */
901 143 : rhs = transformAssignmentIndirection(pstate,
902 : NULL,
903 : targetName,
904 : true,
905 : typeNeeded,
906 : arrayTypMod,
907 : collationNeeded,
908 : next_indirection,
909 : rhs,
910 : location);
911 :
912 : /* process subscripts */
913 143 : result = (Node *) transformArraySubscripts(pstate,
914 : basenode,
915 : arrayType,
916 : elementTypeId,
917 : arrayTypMod,
918 : subscripts,
919 : rhs);
920 :
921 : /* If target was a domain over array, need to coerce up to the domain */
922 143 : if (arrayType != targetTypeId)
923 : {
924 22 : Oid resulttype = exprType(result);
925 :
926 22 : result = coerce_to_target_type(pstate,
927 : result, resulttype,
928 : targetTypeId, targetTypMod,
929 : COERCION_ASSIGNMENT,
930 : COERCE_IMPLICIT_CAST,
931 : -1);
932 : /* can fail if we had int2vector/oidvector, but not for true domains */
933 22 : if (result == NULL)
934 0 : ereport(ERROR,
935 : (errcode(ERRCODE_CANNOT_COERCE),
936 : errmsg("cannot cast type %s to %s",
937 : format_type_be(resulttype),
938 : format_type_be(targetTypeId)),
939 : parser_errposition(pstate, location)));
940 : }
941 :
942 143 : return result;
943 : }
944 :
945 :
946 : /*
947 : * checkInsertTargets -
948 : * generate a list of INSERT column targets if not supplied, or
949 : * test supplied column names to make sure they are in target table.
950 : * Also return an integer list of the columns' attribute numbers.
951 : */
952 : List *
953 3668 : checkInsertTargets(ParseState *pstate, List *cols, List **attrnos)
954 : {
955 3668 : *attrnos = NIL;
956 :
957 3668 : if (cols == NIL)
958 : {
959 : /*
960 : * Generate default column list for INSERT.
961 : */
962 2906 : int numcol = pstate->p_target_relation->rd_rel->relnatts;
963 : int i;
964 :
965 9857 : for (i = 0; i < numcol; i++)
966 : {
967 : ResTarget *col;
968 : Form_pg_attribute attr;
969 :
970 6951 : attr = TupleDescAttr(pstate->p_target_relation->rd_att, i);
971 :
972 6951 : if (attr->attisdropped)
973 12 : continue;
974 :
975 6939 : col = makeNode(ResTarget);
976 6939 : col->name = pstrdup(NameStr(attr->attname));
977 6939 : col->indirection = NIL;
978 6939 : col->val = NULL;
979 6939 : col->location = -1;
980 6939 : cols = lappend(cols, col);
981 6939 : *attrnos = lappend_int(*attrnos, i + 1);
982 : }
983 : }
984 : else
985 : {
986 : /*
987 : * Do initial validation of user-supplied INSERT column list.
988 : */
989 762 : Bitmapset *wholecols = NULL;
990 762 : Bitmapset *partialcols = NULL;
991 : ListCell *tl;
992 :
993 2025 : foreach(tl, cols)
994 : {
995 1271 : ResTarget *col = (ResTarget *) lfirst(tl);
996 1271 : char *name = col->name;
997 : int attrno;
998 :
999 : /* Lookup column name, ereport on failure */
1000 1271 : attrno = attnameAttNum(pstate->p_target_relation, name, false);
1001 1271 : if (attrno == InvalidAttrNumber)
1002 8 : ereport(ERROR,
1003 : (errcode(ERRCODE_UNDEFINED_COLUMN),
1004 : errmsg("column \"%s\" of relation \"%s\" does not exist",
1005 : name,
1006 : RelationGetRelationName(pstate->p_target_relation)),
1007 : parser_errposition(pstate, col->location)));
1008 :
1009 : /*
1010 : * Check for duplicates, but only of whole columns --- we allow
1011 : * INSERT INTO foo (col.subcol1, col.subcol2)
1012 : */
1013 1263 : if (col->indirection == NIL)
1014 : {
1015 : /* whole column; must not have any other assignment */
1016 2420 : if (bms_is_member(attrno, wholecols) ||
1017 1210 : bms_is_member(attrno, partialcols))
1018 0 : ereport(ERROR,
1019 : (errcode(ERRCODE_DUPLICATE_COLUMN),
1020 : errmsg("column \"%s\" specified more than once",
1021 : name),
1022 : parser_errposition(pstate, col->location)));
1023 1210 : wholecols = bms_add_member(wholecols, attrno);
1024 : }
1025 : else
1026 : {
1027 : /* partial column; must not have any whole assignment */
1028 53 : if (bms_is_member(attrno, wholecols))
1029 0 : ereport(ERROR,
1030 : (errcode(ERRCODE_DUPLICATE_COLUMN),
1031 : errmsg("column \"%s\" specified more than once",
1032 : name),
1033 : parser_errposition(pstate, col->location)));
1034 53 : partialcols = bms_add_member(partialcols, attrno);
1035 : }
1036 :
1037 1263 : *attrnos = lappend_int(*attrnos, attrno);
1038 : }
1039 : }
1040 :
1041 3660 : return cols;
1042 : }
1043 :
1044 : /*
1045 : * ExpandColumnRefStar()
1046 : * Transforms foo.* into a list of expressions or targetlist entries.
1047 : *
1048 : * This handles the case where '*' appears as the last or only item in a
1049 : * ColumnRef. The code is shared between the case of foo.* at the top level
1050 : * in a SELECT target list (where we want TargetEntry nodes in the result)
1051 : * and foo.* in a ROW() or VALUES() construct (where we want just bare
1052 : * expressions).
1053 : *
1054 : * The referenced columns are marked as requiring SELECT access.
1055 : */
1056 : static List *
1057 3363 : ExpandColumnRefStar(ParseState *pstate, ColumnRef *cref,
1058 : bool make_target_entry)
1059 : {
1060 3363 : List *fields = cref->fields;
1061 3363 : int numnames = list_length(fields);
1062 :
1063 3363 : if (numnames == 1)
1064 : {
1065 : /*
1066 : * Target item is a bare '*', expand all tables
1067 : *
1068 : * (e.g., SELECT * FROM emp, dept)
1069 : *
1070 : * Since the grammar only accepts bare '*' at top level of SELECT, we
1071 : * need not handle the make_target_entry==false case here.
1072 : */
1073 3044 : Assert(make_target_entry);
1074 3044 : return ExpandAllTables(pstate, cref->location);
1075 : }
1076 : else
1077 : {
1078 : /*
1079 : * Target item is relation.*, expand that table
1080 : *
1081 : * (e.g., SELECT emp.*, dname FROM emp, dept)
1082 : *
1083 : * Note: this code is a lot like transformColumnRef; it's tempting to
1084 : * call that instead and then replace the resulting whole-row Var with
1085 : * a list of Vars. However, that would leave us with the RTE's
1086 : * selectedCols bitmap showing the whole row as needing select
1087 : * permission, as well as the individual columns. That would be
1088 : * incorrect (since columns added later shouldn't need select
1089 : * permissions). We could try to remove the whole-row permission bit
1090 : * after the fact, but duplicating code is less messy.
1091 : */
1092 319 : char *nspname = NULL;
1093 319 : char *relname = NULL;
1094 319 : RangeTblEntry *rte = NULL;
1095 : int levels_up;
1096 : enum
1097 : {
1098 : CRSERR_NO_RTE,
1099 : CRSERR_WRONG_DB,
1100 : CRSERR_TOO_MANY
1101 319 : } crserr = CRSERR_NO_RTE;
1102 :
1103 : /*
1104 : * Give the PreParseColumnRefHook, if any, first shot. If it returns
1105 : * non-null then we should use that expression.
1106 : */
1107 319 : if (pstate->p_pre_columnref_hook != NULL)
1108 : {
1109 : Node *node;
1110 :
1111 4 : node = (*pstate->p_pre_columnref_hook) (pstate, cref);
1112 4 : if (node != NULL)
1113 0 : return ExpandRowReference(pstate, node, make_target_entry);
1114 : }
1115 :
1116 319 : switch (numnames)
1117 : {
1118 : case 2:
1119 319 : relname = strVal(linitial(fields));
1120 319 : rte = refnameRangeTblEntry(pstate, nspname, relname,
1121 : cref->location,
1122 : &levels_up);
1123 319 : break;
1124 : case 3:
1125 0 : nspname = strVal(linitial(fields));
1126 0 : relname = strVal(lsecond(fields));
1127 0 : rte = refnameRangeTblEntry(pstate, nspname, relname,
1128 : cref->location,
1129 : &levels_up);
1130 0 : break;
1131 : case 4:
1132 : {
1133 0 : char *catname = strVal(linitial(fields));
1134 :
1135 : /*
1136 : * We check the catalog name and then ignore it.
1137 : */
1138 0 : if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
1139 : {
1140 0 : crserr = CRSERR_WRONG_DB;
1141 0 : break;
1142 : }
1143 0 : nspname = strVal(lsecond(fields));
1144 0 : relname = strVal(lthird(fields));
1145 0 : rte = refnameRangeTblEntry(pstate, nspname, relname,
1146 : cref->location,
1147 : &levels_up);
1148 0 : break;
1149 : }
1150 : default:
1151 0 : crserr = CRSERR_TOO_MANY;
1152 0 : break;
1153 : }
1154 :
1155 : /*
1156 : * Now give the PostParseColumnRefHook, if any, a chance. We cheat a
1157 : * bit by passing the RangeTblEntry, not a Var, as the planned
1158 : * translation. (A single Var wouldn't be strictly correct anyway.
1159 : * This convention allows hooks that really care to know what is
1160 : * happening.)
1161 : */
1162 319 : if (pstate->p_post_columnref_hook != NULL)
1163 : {
1164 : Node *node;
1165 :
1166 11 : node = (*pstate->p_post_columnref_hook) (pstate, cref,
1167 : (Node *) rte);
1168 11 : if (node != NULL)
1169 : {
1170 11 : if (rte != NULL)
1171 0 : ereport(ERROR,
1172 : (errcode(ERRCODE_AMBIGUOUS_COLUMN),
1173 : errmsg("column reference \"%s\" is ambiguous",
1174 : NameListToString(cref->fields)),
1175 : parser_errposition(pstate, cref->location)));
1176 11 : return ExpandRowReference(pstate, node, make_target_entry);
1177 : }
1178 : }
1179 :
1180 : /*
1181 : * Throw error if no translation found.
1182 : */
1183 308 : if (rte == NULL)
1184 : {
1185 1 : switch (crserr)
1186 : {
1187 : case CRSERR_NO_RTE:
1188 1 : errorMissingRTE(pstate, makeRangeVar(nspname, relname,
1189 : cref->location));
1190 : break;
1191 : case CRSERR_WRONG_DB:
1192 0 : ereport(ERROR,
1193 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1194 : errmsg("cross-database references are not implemented: %s",
1195 : NameListToString(cref->fields)),
1196 : parser_errposition(pstate, cref->location)));
1197 : break;
1198 : case CRSERR_TOO_MANY:
1199 0 : ereport(ERROR,
1200 : (errcode(ERRCODE_SYNTAX_ERROR),
1201 : errmsg("improper qualified name (too many dotted names): %s",
1202 : NameListToString(cref->fields)),
1203 : parser_errposition(pstate, cref->location)));
1204 : break;
1205 : }
1206 : }
1207 :
1208 : /*
1209 : * OK, expand the RTE into fields.
1210 : */
1211 307 : return ExpandSingleTable(pstate, rte, cref->location, make_target_entry);
1212 : }
1213 : }
1214 :
1215 : /*
1216 : * ExpandAllTables()
1217 : * Transforms '*' (in the target list) into a list of targetlist entries.
1218 : *
1219 : * tlist entries are generated for each relation visible for unqualified
1220 : * column name access. We do not consider qualified-name-only entries because
1221 : * that would include input tables of aliasless JOINs, NEW/OLD pseudo-entries,
1222 : * etc.
1223 : *
1224 : * The referenced relations/columns are marked as requiring SELECT access.
1225 : */
1226 : static List *
1227 3044 : ExpandAllTables(ParseState *pstate, int location)
1228 : {
1229 3044 : List *target = NIL;
1230 3044 : bool found_table = false;
1231 : ListCell *l;
1232 :
1233 6676 : foreach(l, pstate->p_namespace)
1234 : {
1235 3632 : ParseNamespaceItem *nsitem = (ParseNamespaceItem *) lfirst(l);
1236 3632 : RangeTblEntry *rte = nsitem->p_rte;
1237 :
1238 : /* Ignore table-only items */
1239 3632 : if (!nsitem->p_cols_visible)
1240 458 : continue;
1241 : /* Should not have any lateral-only items when parsing targetlist */
1242 3174 : Assert(!nsitem->p_lateral_only);
1243 : /* Remember we found a p_cols_visible item */
1244 3174 : found_table = true;
1245 :
1246 3174 : target = list_concat(target,
1247 : expandRelAttrs(pstate,
1248 : rte,
1249 : RTERangeTablePosn(pstate, rte,
1250 : NULL),
1251 : 0,
1252 : location));
1253 : }
1254 :
1255 : /*
1256 : * Check for "SELECT *;". We do it this way, rather than checking for
1257 : * target == NIL, because we want to allow SELECT * FROM a zero_column
1258 : * table.
1259 : */
1260 3044 : if (!found_table)
1261 0 : ereport(ERROR,
1262 : (errcode(ERRCODE_SYNTAX_ERROR),
1263 : errmsg("SELECT * with no tables specified is not valid"),
1264 : parser_errposition(pstate, location)));
1265 :
1266 3044 : return target;
1267 : }
1268 :
1269 : /*
1270 : * ExpandIndirectionStar()
1271 : * Transforms foo.* into a list of expressions or targetlist entries.
1272 : *
1273 : * This handles the case where '*' appears as the last item in A_Indirection.
1274 : * The code is shared between the case of foo.* at the top level in a SELECT
1275 : * target list (where we want TargetEntry nodes in the result) and foo.* in
1276 : * a ROW() or VALUES() construct (where we want just bare expressions).
1277 : * For robustness, we use a separate "make_target_entry" flag to control
1278 : * this rather than relying on exprKind.
1279 : */
1280 : static List *
1281 22 : ExpandIndirectionStar(ParseState *pstate, A_Indirection *ind,
1282 : bool make_target_entry, ParseExprKind exprKind)
1283 : {
1284 : Node *expr;
1285 :
1286 : /* Strip off the '*' to create a reference to the rowtype object */
1287 22 : ind = copyObject(ind);
1288 22 : ind->indirection = list_truncate(ind->indirection,
1289 22 : list_length(ind->indirection) - 1);
1290 :
1291 : /* And transform that */
1292 22 : expr = transformExpr(pstate, (Node *) ind, exprKind);
1293 :
1294 : /* Expand the rowtype expression into individual fields */
1295 22 : return ExpandRowReference(pstate, expr, make_target_entry);
1296 : }
1297 :
1298 : /*
1299 : * ExpandSingleTable()
1300 : * Transforms foo.* into a list of expressions or targetlist entries.
1301 : *
1302 : * This handles the case where foo has been determined to be a simple
1303 : * reference to an RTE, so we can just generate Vars for the expressions.
1304 : *
1305 : * The referenced columns are marked as requiring SELECT access.
1306 : */
1307 : static List *
1308 307 : ExpandSingleTable(ParseState *pstate, RangeTblEntry *rte,
1309 : int location, bool make_target_entry)
1310 : {
1311 : int sublevels_up;
1312 : int rtindex;
1313 :
1314 307 : rtindex = RTERangeTablePosn(pstate, rte, &sublevels_up);
1315 :
1316 307 : if (make_target_entry)
1317 : {
1318 : /* expandRelAttrs handles permissions marking */
1319 284 : return expandRelAttrs(pstate, rte, rtindex, sublevels_up,
1320 : location);
1321 : }
1322 : else
1323 : {
1324 : List *vars;
1325 : ListCell *l;
1326 :
1327 23 : expandRTE(rte, rtindex, sublevels_up, location, false,
1328 : NULL, &vars);
1329 :
1330 : /*
1331 : * Require read access to the table. This is normally redundant with
1332 : * the markVarForSelectPriv calls below, but not if the table has zero
1333 : * columns.
1334 : */
1335 23 : rte->requiredPerms |= ACL_SELECT;
1336 :
1337 : /* Require read access to each column */
1338 61 : foreach(l, vars)
1339 : {
1340 38 : Var *var = (Var *) lfirst(l);
1341 :
1342 38 : markVarForSelectPriv(pstate, var, rte);
1343 : }
1344 :
1345 23 : return vars;
1346 : }
1347 : }
1348 :
1349 : /*
1350 : * ExpandRowReference()
1351 : * Transforms foo.* into a list of expressions or targetlist entries.
1352 : *
1353 : * This handles the case where foo is an arbitrary expression of composite
1354 : * type.
1355 : */
1356 : static List *
1357 33 : ExpandRowReference(ParseState *pstate, Node *expr,
1358 : bool make_target_entry)
1359 : {
1360 33 : List *result = NIL;
1361 : TupleDesc tupleDesc;
1362 : int numAttrs;
1363 : int i;
1364 :
1365 : /*
1366 : * If the rowtype expression is a whole-row Var, we can expand the fields
1367 : * as simple Vars. Note: if the RTE is a relation, this case leaves us
1368 : * with the RTE's selectedCols bitmap showing the whole row as needing
1369 : * select permission, as well as the individual columns. However, we can
1370 : * only get here for weird notations like (table.*).*, so it's not worth
1371 : * trying to clean up --- arguably, the permissions marking is correct
1372 : * anyway for such cases.
1373 : */
1374 39 : if (IsA(expr, Var) &&
1375 6 : ((Var *) expr)->varattno == InvalidAttrNumber)
1376 : {
1377 0 : Var *var = (Var *) expr;
1378 : RangeTblEntry *rte;
1379 :
1380 0 : rte = GetRTEByRangeTablePosn(pstate, var->varno, var->varlevelsup);
1381 0 : return ExpandSingleTable(pstate, rte, var->location, make_target_entry);
1382 : }
1383 :
1384 : /*
1385 : * Otherwise we have to do it the hard way. Our current implementation is
1386 : * to generate multiple copies of the expression and do FieldSelects.
1387 : * (This can be pretty inefficient if the expression involves nontrivial
1388 : * computation :-(.)
1389 : *
1390 : * Verify it's a composite type, and get the tupdesc. We use
1391 : * get_expr_result_type() because that can handle references to functions
1392 : * returning anonymous record types. If that fails, use
1393 : * lookup_rowtype_tupdesc(), which will almost certainly fail as well, but
1394 : * it will give an appropriate error message.
1395 : *
1396 : * If it's a Var of type RECORD, we have to work even harder: we have to
1397 : * find what the Var refers to, and pass that to get_expr_result_type.
1398 : * That task is handled by expandRecordVariable().
1399 : */
1400 39 : if (IsA(expr, Var) &&
1401 6 : ((Var *) expr)->vartype == RECORDOID)
1402 0 : tupleDesc = expandRecordVariable(pstate, (Var *) expr, 0);
1403 33 : else if (get_expr_result_type(expr, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
1404 0 : tupleDesc = lookup_rowtype_tupdesc_copy(exprType(expr),
1405 : exprTypmod(expr));
1406 33 : Assert(tupleDesc);
1407 :
1408 : /* Generate a list of references to the individual fields */
1409 33 : numAttrs = tupleDesc->natts;
1410 159 : for (i = 0; i < numAttrs; i++)
1411 : {
1412 126 : Form_pg_attribute att = TupleDescAttr(tupleDesc, i);
1413 : FieldSelect *fselect;
1414 :
1415 126 : if (att->attisdropped)
1416 0 : continue;
1417 :
1418 126 : fselect = makeNode(FieldSelect);
1419 126 : fselect->arg = (Expr *) copyObject(expr);
1420 126 : fselect->fieldnum = i + 1;
1421 126 : fselect->resulttype = att->atttypid;
1422 126 : fselect->resulttypmod = att->atttypmod;
1423 : /* save attribute's collation for parse_collate.c */
1424 126 : fselect->resultcollid = att->attcollation;
1425 :
1426 126 : if (make_target_entry)
1427 : {
1428 : /* add TargetEntry decoration */
1429 : TargetEntry *te;
1430 :
1431 200 : te = makeTargetEntry((Expr *) fselect,
1432 100 : (AttrNumber) pstate->p_next_resno++,
1433 100 : pstrdup(NameStr(att->attname)),
1434 : false);
1435 100 : result = lappend(result, te);
1436 : }
1437 : else
1438 26 : result = lappend(result, fselect);
1439 : }
1440 :
1441 33 : return result;
1442 : }
1443 :
1444 : /*
1445 : * expandRecordVariable
1446 : * Get the tuple descriptor for a Var of type RECORD, if possible.
1447 : *
1448 : * Since no actual table or view column is allowed to have type RECORD, such
1449 : * a Var must refer to a JOIN or FUNCTION RTE or to a subquery output. We
1450 : * drill down to find the ultimate defining expression and attempt to infer
1451 : * the tupdesc from it. We ereport if we can't determine the tupdesc.
1452 : *
1453 : * levelsup is an extra offset to interpret the Var's varlevelsup correctly.
1454 : */
1455 : TupleDesc
1456 19 : expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
1457 : {
1458 : TupleDesc tupleDesc;
1459 : int netlevelsup;
1460 : RangeTblEntry *rte;
1461 : AttrNumber attnum;
1462 : Node *expr;
1463 :
1464 : /* Check my caller didn't mess up */
1465 19 : Assert(IsA(var, Var));
1466 19 : Assert(var->vartype == RECORDOID);
1467 :
1468 19 : netlevelsup = var->varlevelsup + levelsup;
1469 19 : rte = GetRTEByRangeTablePosn(pstate, var->varno, netlevelsup);
1470 19 : attnum = var->varattno;
1471 :
1472 19 : if (attnum == InvalidAttrNumber)
1473 : {
1474 : /* Whole-row reference to an RTE, so expand the known fields */
1475 : List *names,
1476 : *vars;
1477 : ListCell *lname,
1478 : *lvar;
1479 : int i;
1480 :
1481 0 : expandRTE(rte, var->varno, 0, var->location, false,
1482 : &names, &vars);
1483 :
1484 0 : tupleDesc = CreateTemplateTupleDesc(list_length(vars), false);
1485 0 : i = 1;
1486 0 : forboth(lname, names, lvar, vars)
1487 : {
1488 0 : char *label = strVal(lfirst(lname));
1489 0 : Node *varnode = (Node *) lfirst(lvar);
1490 :
1491 0 : TupleDescInitEntry(tupleDesc, i,
1492 : label,
1493 : exprType(varnode),
1494 : exprTypmod(varnode),
1495 : 0);
1496 0 : TupleDescInitEntryCollation(tupleDesc, i,
1497 : exprCollation(varnode));
1498 0 : i++;
1499 : }
1500 0 : Assert(lname == NULL && lvar == NULL); /* lists same length? */
1501 :
1502 0 : return tupleDesc;
1503 : }
1504 :
1505 19 : expr = (Node *) var; /* default if we can't drill down */
1506 :
1507 19 : switch (rte->rtekind)
1508 : {
1509 : case RTE_RELATION:
1510 : case RTE_VALUES:
1511 : case RTE_NAMEDTUPLESTORE:
1512 :
1513 : /*
1514 : * This case should not occur: a column of a table or values list
1515 : * shouldn't have type RECORD. Fall through and fail (most
1516 : * likely) at the bottom.
1517 : */
1518 0 : break;
1519 : case RTE_SUBQUERY:
1520 : {
1521 : /* Subselect-in-FROM: examine sub-select's output expr */
1522 19 : TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
1523 : attnum);
1524 :
1525 19 : if (ste == NULL || ste->resjunk)
1526 0 : elog(ERROR, "subquery %s does not have attribute %d",
1527 : rte->eref->aliasname, attnum);
1528 19 : expr = (Node *) ste->expr;
1529 19 : if (IsA(expr, Var))
1530 : {
1531 : /*
1532 : * Recurse into the sub-select to see what its Var refers
1533 : * to. We have to build an additional level of ParseState
1534 : * to keep in step with varlevelsup in the subselect.
1535 : */
1536 : ParseState mypstate;
1537 :
1538 0 : MemSet(&mypstate, 0, sizeof(mypstate));
1539 0 : mypstate.parentParseState = pstate;
1540 0 : mypstate.p_rtable = rte->subquery->rtable;
1541 : /* don't bother filling the rest of the fake pstate */
1542 :
1543 0 : return expandRecordVariable(&mypstate, (Var *) expr, 0);
1544 : }
1545 : /* else fall through to inspect the expression */
1546 : }
1547 19 : break;
1548 : case RTE_JOIN:
1549 : /* Join RTE --- recursively inspect the alias variable */
1550 0 : Assert(attnum > 0 && attnum <= list_length(rte->joinaliasvars));
1551 0 : expr = (Node *) list_nth(rte->joinaliasvars, attnum - 1);
1552 0 : Assert(expr != NULL);
1553 : /* We intentionally don't strip implicit coercions here */
1554 0 : if (IsA(expr, Var))
1555 0 : return expandRecordVariable(pstate, (Var *) expr, netlevelsup);
1556 : /* else fall through to inspect the expression */
1557 0 : break;
1558 : case RTE_FUNCTION:
1559 :
1560 : /*
1561 : * We couldn't get here unless a function is declared with one of
1562 : * its result columns as RECORD, which is not allowed.
1563 : */
1564 0 : break;
1565 : case RTE_TABLEFUNC:
1566 :
1567 : /*
1568 : * Table function cannot have columns with RECORD type.
1569 : */
1570 0 : break;
1571 : case RTE_CTE:
1572 : /* CTE reference: examine subquery's output expr */
1573 0 : if (!rte->self_reference)
1574 : {
1575 0 : CommonTableExpr *cte = GetCTEForRTE(pstate, rte, netlevelsup);
1576 : TargetEntry *ste;
1577 :
1578 0 : ste = get_tle_by_resno(GetCTETargetList(cte), attnum);
1579 0 : if (ste == NULL || ste->resjunk)
1580 0 : elog(ERROR, "subquery %s does not have attribute %d",
1581 : rte->eref->aliasname, attnum);
1582 0 : expr = (Node *) ste->expr;
1583 0 : if (IsA(expr, Var))
1584 : {
1585 : /*
1586 : * Recurse into the CTE to see what its Var refers to. We
1587 : * have to build an additional level of ParseState to keep
1588 : * in step with varlevelsup in the CTE; furthermore it
1589 : * could be an outer CTE.
1590 : */
1591 : ParseState mypstate;
1592 : Index levelsup;
1593 :
1594 0 : MemSet(&mypstate, 0, sizeof(mypstate));
1595 : /* this loop must work, since GetCTEForRTE did */
1596 0 : for (levelsup = 0;
1597 0 : levelsup < rte->ctelevelsup + netlevelsup;
1598 0 : levelsup++)
1599 0 : pstate = pstate->parentParseState;
1600 0 : mypstate.parentParseState = pstate;
1601 0 : mypstate.p_rtable = ((Query *) cte->ctequery)->rtable;
1602 : /* don't bother filling the rest of the fake pstate */
1603 :
1604 0 : return expandRecordVariable(&mypstate, (Var *) expr, 0);
1605 : }
1606 : /* else fall through to inspect the expression */
1607 : }
1608 0 : break;
1609 : }
1610 :
1611 : /*
1612 : * We now have an expression we can't expand any more, so see if
1613 : * get_expr_result_type() can do anything with it. If not, pass to
1614 : * lookup_rowtype_tupdesc() which will probably fail, but will give an
1615 : * appropriate error message while failing.
1616 : */
1617 19 : if (get_expr_result_type(expr, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
1618 0 : tupleDesc = lookup_rowtype_tupdesc_copy(exprType(expr),
1619 : exprTypmod(expr));
1620 :
1621 19 : return tupleDesc;
1622 : }
1623 :
1624 :
1625 : /*
1626 : * FigureColname -
1627 : * if the name of the resulting column is not specified in the target
1628 : * list, we have to guess a suitable name. The SQL spec provides some
1629 : * guidance, but not much...
1630 : *
1631 : * Note that the argument is the *untransformed* parse tree for the target
1632 : * item. This is a shade easier to work with than the transformed tree.
1633 : */
1634 : char *
1635 31713 : FigureColname(Node *node)
1636 : {
1637 31713 : char *name = NULL;
1638 :
1639 31713 : (void) FigureColnameInternal(node, &name);
1640 31713 : if (name != NULL)
1641 28330 : return name;
1642 : /* default result if we can't guess anything */
1643 3383 : return "?column?";
1644 : }
1645 :
1646 : /*
1647 : * FigureIndexColname -
1648 : * choose the name for an expression column in an index
1649 : *
1650 : * This is actually just like FigureColname, except we return NULL if
1651 : * we can't pick a good name.
1652 : */
1653 : char *
1654 36 : FigureIndexColname(Node *node)
1655 : {
1656 36 : char *name = NULL;
1657 :
1658 36 : (void) FigureColnameInternal(node, &name);
1659 36 : return name;
1660 : }
1661 :
1662 : /*
1663 : * FigureColnameInternal -
1664 : * internal workhorse for FigureColname
1665 : *
1666 : * Return value indicates strength of confidence in result:
1667 : * 0 - no information
1668 : * 1 - second-best name choice
1669 : * 2 - good name choice
1670 : * The return value is actually only used internally.
1671 : * If the result isn't zero, *name is set to the chosen name.
1672 : */
1673 : static int
1674 34555 : FigureColnameInternal(Node *node, char **name)
1675 : {
1676 34555 : int strength = 0;
1677 :
1678 34555 : if (node == NULL)
1679 3 : return strength;
1680 :
1681 34552 : switch (nodeTag(node))
1682 : {
1683 : case T_ColumnRef:
1684 : {
1685 13382 : char *fname = NULL;
1686 : ListCell *l;
1687 :
1688 : /* find last field name, if any, ignoring "*" */
1689 34271 : foreach(l, ((ColumnRef *) node)->fields)
1690 : {
1691 20889 : Node *i = lfirst(l);
1692 :
1693 20889 : if (IsA(i, String))
1694 20881 : fname = strVal(i);
1695 : }
1696 13382 : if (fname)
1697 : {
1698 13382 : *name = fname;
1699 13382 : return 2;
1700 : }
1701 : }
1702 0 : break;
1703 : case T_A_Indirection:
1704 : {
1705 138 : A_Indirection *ind = (A_Indirection *) node;
1706 138 : char *fname = NULL;
1707 : ListCell *l;
1708 :
1709 : /* find last field name, if any, ignoring "*" and subscripts */
1710 314 : foreach(l, ind->indirection)
1711 : {
1712 176 : Node *i = lfirst(l);
1713 :
1714 176 : if (IsA(i, String))
1715 32 : fname = strVal(i);
1716 : }
1717 138 : if (fname)
1718 : {
1719 29 : *name = fname;
1720 29 : return 2;
1721 : }
1722 109 : return FigureColnameInternal(ind->arg, name);
1723 : }
1724 : break;
1725 : case T_FuncCall:
1726 13557 : *name = strVal(llast(((FuncCall *) node)->funcname));
1727 13557 : return 2;
1728 : case T_A_Expr:
1729 1795 : if (((A_Expr *) node)->kind == AEXPR_NULLIF)
1730 : {
1731 : /* make nullif() act like a regular function */
1732 3 : *name = "nullif";
1733 3 : return 2;
1734 : }
1735 1792 : if (((A_Expr *) node)->kind == AEXPR_PAREN)
1736 : {
1737 : /* look through dummy parenthesis node */
1738 0 : return FigureColnameInternal(((A_Expr *) node)->lexpr, name);
1739 : }
1740 1792 : break;
1741 : case T_TypeCast:
1742 2216 : strength = FigureColnameInternal(((TypeCast *) node)->arg,
1743 : name);
1744 2216 : if (strength <= 1)
1745 : {
1746 807 : if (((TypeCast *) node)->typeName != NULL)
1747 : {
1748 807 : *name = strVal(llast(((TypeCast *) node)->typeName->names));
1749 807 : return 1;
1750 : }
1751 : }
1752 1409 : break;
1753 : case T_CollateClause:
1754 5 : return FigureColnameInternal(((CollateClause *) node)->arg, name);
1755 : case T_GroupingFunc:
1756 : /* make GROUPING() act like a regular function */
1757 36 : *name = "grouping";
1758 36 : return 2;
1759 : case T_SubLink:
1760 344 : switch (((SubLink *) node)->subLinkType)
1761 : {
1762 : case EXISTS_SUBLINK:
1763 5 : *name = "exists";
1764 5 : return 2;
1765 : case ARRAY_SUBLINK:
1766 10 : *name = "array";
1767 10 : return 2;
1768 : case EXPR_SUBLINK:
1769 : {
1770 : /* Get column name of the subquery's single target */
1771 326 : SubLink *sublink = (SubLink *) node;
1772 326 : Query *query = (Query *) sublink->subselect;
1773 :
1774 : /*
1775 : * The subquery has probably already been transformed,
1776 : * but let's be careful and check that. (The reason
1777 : * we can see a transformed subquery here is that
1778 : * transformSubLink is lazy and modifies the SubLink
1779 : * node in-place.)
1780 : */
1781 326 : if (IsA(query, Query))
1782 : {
1783 326 : TargetEntry *te = (TargetEntry *) linitial(query->targetList);
1784 :
1785 326 : if (te->resname)
1786 : {
1787 326 : *name = te->resname;
1788 326 : return 2;
1789 : }
1790 : }
1791 : }
1792 0 : break;
1793 : /* As with other operator-like nodes, these have no names */
1794 : case MULTIEXPR_SUBLINK:
1795 : case ALL_SUBLINK:
1796 : case ANY_SUBLINK:
1797 : case ROWCOMPARE_SUBLINK:
1798 : case CTE_SUBLINK:
1799 3 : break;
1800 : }
1801 3 : break;
1802 : case T_CaseExpr:
1803 476 : strength = FigureColnameInternal((Node *) ((CaseExpr *) node)->defresult,
1804 : name);
1805 476 : if (strength <= 1)
1806 : {
1807 61 : *name = "case";
1808 61 : return 1;
1809 : }
1810 415 : break;
1811 : case T_A_ArrayExpr:
1812 : /* make ARRAY[] act like a function */
1813 41 : *name = "array";
1814 41 : return 2;
1815 : case T_RowExpr:
1816 : /* make ROW() act like a function */
1817 34 : *name = "row";
1818 34 : return 2;
1819 : case T_CoalesceExpr:
1820 : /* make coalesce() act like a regular function */
1821 42 : *name = "coalesce";
1822 42 : return 2;
1823 : case T_MinMaxExpr:
1824 : /* make greatest/least act like a regular function */
1825 10 : switch (((MinMaxExpr *) node)->op)
1826 : {
1827 : case IS_GREATEST:
1828 4 : *name = "greatest";
1829 4 : return 2;
1830 : case IS_LEAST:
1831 6 : *name = "least";
1832 6 : return 2;
1833 : }
1834 0 : break;
1835 : case T_SQLValueFunction:
1836 : /* make these act like a function or variable */
1837 12 : switch (((SQLValueFunction *) node)->op)
1838 : {
1839 : case SVFOP_CURRENT_DATE:
1840 2 : *name = "current_date";
1841 2 : return 2;
1842 : case SVFOP_CURRENT_TIME:
1843 : case SVFOP_CURRENT_TIME_N:
1844 0 : *name = "current_time";
1845 0 : return 2;
1846 : case SVFOP_CURRENT_TIMESTAMP:
1847 : case SVFOP_CURRENT_TIMESTAMP_N:
1848 0 : *name = "current_timestamp";
1849 0 : return 2;
1850 : case SVFOP_LOCALTIME:
1851 : case SVFOP_LOCALTIME_N:
1852 0 : *name = "localtime";
1853 0 : return 2;
1854 : case SVFOP_LOCALTIMESTAMP:
1855 : case SVFOP_LOCALTIMESTAMP_N:
1856 1 : *name = "localtimestamp";
1857 1 : return 2;
1858 : case SVFOP_CURRENT_ROLE:
1859 0 : *name = "current_role";
1860 0 : return 2;
1861 : case SVFOP_CURRENT_USER:
1862 3 : *name = "current_user";
1863 3 : return 2;
1864 : case SVFOP_USER:
1865 0 : *name = "user";
1866 0 : return 2;
1867 : case SVFOP_SESSION_USER:
1868 3 : *name = "session_user";
1869 3 : return 2;
1870 : case SVFOP_CURRENT_CATALOG:
1871 0 : *name = "current_catalog";
1872 0 : return 2;
1873 : case SVFOP_CURRENT_SCHEMA:
1874 3 : *name = "current_schema";
1875 3 : return 2;
1876 : }
1877 0 : break;
1878 : case T_XmlExpr:
1879 : /* make SQL/XML functions act like a regular function */
1880 25 : switch (((XmlExpr *) node)->op)
1881 : {
1882 : case IS_XMLCONCAT:
1883 2 : *name = "xmlconcat";
1884 2 : return 2;
1885 : case IS_XMLELEMENT:
1886 0 : *name = "xmlelement";
1887 0 : return 2;
1888 : case IS_XMLFOREST:
1889 0 : *name = "xmlforest";
1890 0 : return 2;
1891 : case IS_XMLPARSE:
1892 23 : *name = "xmlparse";
1893 23 : return 2;
1894 : case IS_XMLPI:
1895 0 : *name = "xmlpi";
1896 0 : return 2;
1897 : case IS_XMLROOT:
1898 0 : *name = "xmlroot";
1899 0 : return 2;
1900 : case IS_XMLSERIALIZE:
1901 0 : *name = "xmlserialize";
1902 0 : return 2;
1903 : case IS_DOCUMENT:
1904 : /* nothing */
1905 0 : break;
1906 : }
1907 0 : break;
1908 : case T_XmlSerialize:
1909 1 : *name = "xmlserialize";
1910 1 : return 2;
1911 : default:
1912 2438 : break;
1913 : }
1914 :
1915 6057 : return strength;
1916 : }
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