*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.131 2005/04/06 16:34:06 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.132 2005/04/25 21:03:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "commands/dbcommands.h"
+#include "funcapi.h"
#include "miscadmin.h"
#include "nodes/bitmapset.h"
#include "nodes/makefuncs.h"
static List *ExpandColumnRefStar(ParseState *pstate, ColumnRef *cref);
static List *ExpandAllTables(ParseState *pstate);
static List *ExpandIndirectionStar(ParseState *pstate, A_Indirection *ind);
+static TupleDesc expandRecordVariable(ParseState *pstate, Var *var,
+ int levelsup);
static int FigureColnameInternal(Node *node, char **name);
/* And transform that */
expr = transformExpr(pstate, (Node *) ind);
- /* Verify it's a composite type, and get the tupdesc */
- tupleDesc = lookup_rowtype_tupdesc(exprType(expr), exprTypmod(expr));
+ /*
+ * Verify it's a composite type, and get the tupdesc. We use
+ * get_expr_result_type() because that can handle references to
+ * functions returning anonymous record types. If that fails,
+ * use lookup_rowtype_tupdesc(), which will almost certainly fail
+ * as well, but it will give an appropriate error message.
+ *
+ * If it's a Var of type RECORD, we have to work even harder: we have
+ * to find what the Var refers to, and pass that to get_expr_result_type.
+ * That task is handled by expandRecordVariable().
+ */
+ if (IsA(expr, Var) &&
+ ((Var *) expr)->vartype == RECORDOID)
+ tupleDesc = expandRecordVariable(pstate, (Var *) expr, 0);
+ else if (get_expr_result_type(expr, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+ tupleDesc = lookup_rowtype_tupdesc(exprType(expr), exprTypmod(expr));
+ Assert(tupleDesc);
/* Generate a list of references to the individual fields */
numAttrs = tupleDesc->natts;
return te_list;
}
+/*
+ * expandRecordVariable
+ * Get the tuple descriptor for a Var of type RECORD, if possible.
+ *
+ * Since no actual table or view column is allowed to have type RECORD, such
+ * a Var must refer to a JOIN or FUNCTION RTE or to a subquery output. We
+ * drill down to find the ultimate defining expression and attempt to infer
+ * the tupdesc from it. We ereport if we can't determine the tupdesc.
+ *
+ * levelsup is an extra offset to interpret the Var's varlevelsup correctly.
+ */
+static TupleDesc
+expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
+{
+ TupleDesc tupleDesc;
+ int netlevelsup;
+ RangeTblEntry *rte;
+ AttrNumber attnum;
+ Node *expr;
+
+ /* Check my caller didn't mess up */
+ Assert(IsA(var, Var));
+ Assert(var->vartype == RECORDOID);
+
+ netlevelsup = var->varlevelsup + levelsup;
+ rte = GetRTEByRangeTablePosn(pstate, var->varno, netlevelsup);
+ attnum = var->varattno;
+
+ expr = (Node *) var; /* default if we can't drill down */
+
+ switch (rte->rtekind)
+ {
+ case RTE_RELATION:
+ case RTE_SPECIAL:
+ /*
+ * This case should not occur: a whole-row Var should have the
+ * table's named rowtype, and a column of a table shouldn't have
+ * type RECORD either. Fall through and fail (most likely)
+ * at the bottom.
+ */
+ break;
+ case RTE_SUBQUERY:
+ {
+ /* Subselect-in-FROM: examine sub-select's output expr */
+ TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
+ attnum);
+
+ if (ste == NULL || ste->resjunk)
+ elog(ERROR, "subquery %s does not have attribute %d",
+ rte->eref->aliasname, attnum);
+ expr = (Node *) ste->expr;
+ if (IsA(expr, Var))
+ {
+ /*
+ * Recurse into the sub-select to see what its Var refers
+ * to. We have to build an additional level of ParseState
+ * to keep in step with varlevelsup in the subselect.
+ */
+ ParseState mypstate;
+
+ MemSet(&mypstate, 0, sizeof(mypstate));
+ mypstate.parentParseState = pstate;
+ mypstate.p_rtable = rte->subquery->rtable;
+ /* don't bother filling the rest of the fake pstate */
+
+ return expandRecordVariable(&mypstate, (Var *) expr, 0);
+ }
+ /* else fall through to inspect the expression */
+ }
+ break;
+ case RTE_JOIN:
+ /* Join RTE */
+ if (attnum == InvalidAttrNumber)
+ {
+ /* Whole-row reference to join, so expand the fields */
+ List *names,
+ *vars;
+ ListCell *lname,
+ *lvar;
+ int i;
+
+ expandRTE(GetLevelNRangeTable(pstate, netlevelsup),
+ var->varno, 0, false, &names, &vars);
+
+ tupleDesc = CreateTemplateTupleDesc(list_length(vars), false);
+ i = 1;
+ forboth(lname, names, lvar, vars)
+ {
+ char *label = strVal(lfirst(lname));
+ Node *varnode = (Node *) lfirst(lvar);
+
+ TupleDescInitEntry(tupleDesc, i,
+ label,
+ exprType(varnode),
+ exprTypmod(varnode),
+ 0);
+ i++;
+ }
+ Assert(lname == NULL && lvar == NULL); /* lists same len? */
+ return tupleDesc;
+ }
+ /* Else recursively inspect the alias variable */
+ Assert(attnum > 0 && attnum <= list_length(rte->joinaliasvars));
+ expr = (Node *) list_nth(rte->joinaliasvars, attnum - 1);
+ if (IsA(expr, Var))
+ return expandRecordVariable(pstate, (Var *) expr, netlevelsup);
+ /* else fall through to inspect the expression */
+ break;
+ case RTE_FUNCTION:
+ expr = rte->funcexpr;
+ /* The func expr probably can't be a Var, but check */
+ if (IsA(expr, Var))
+ return expandRecordVariable(pstate, (Var *) expr, netlevelsup);
+ /* else fall through to inspect the expression */
+ break;
+ }
+
+ /*
+ * We now have an expression we can't expand any more, so see if
+ * get_expr_result_type() can do anything with it. If not, pass
+ * to lookup_rowtype_tupdesc() which will probably fail, but will
+ * give an appropriate error message while failing.
+ */
+ if (get_expr_result_type(expr, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+ tupleDesc = lookup_rowtype_tupdesc(exprType(expr), exprTypmod(expr));
+
+ return tupleDesc;
+}
+
+
/*
* FigureColname -
* if the name of the resulting column is not specified in the target
projects / postgresql / commitdiff