* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.403 2010/08/27 20:30:08 petere Exp $
+ * $PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.404 2010/09/18 18:37:01 tgl Exp $
*
*-------------------------------------------------------------------------
*/
static Query *transformInsertStmt(ParseState *pstate, InsertStmt *stmt);
static List *transformInsertRow(ParseState *pstate, List *exprlist,
List *stmtcols, List *icolumns, List *attrnos);
+static int count_rowexpr_columns(ParseState *pstate, Node *expr);
static Query *transformSelectStmt(ParseState *pstate, SelectStmt *stmt);
static Query *transformValuesClause(ParseState *pstate, SelectStmt *stmt);
static Query *transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt);
list_length(icolumns))))));
if (stmtcols != NIL &&
list_length(exprlist) < list_length(icolumns))
+ {
+ /*
+ * We can get here for cases like INSERT ... SELECT (a,b,c) FROM ...
+ * where the user accidentally created a RowExpr instead of separate
+ * columns. Add a suitable hint if that seems to be the problem,
+ * because the main error message is quite misleading for this case.
+ * (If there's no stmtcols, you'll get something about data type
+ * mismatch, which is less misleading so we don't worry about giving
+ * a hint in that case.)
+ */
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("INSERT has more target columns than expressions"),
+ ((list_length(exprlist) == 1 &&
+ count_rowexpr_columns(pstate, linitial(exprlist)) ==
+ list_length(icolumns)) ?
+ errhint("The insertion source is a row expression containing the same number of columns expected by the INSERT. Did you accidentally use extra parentheses?") : 0),
parser_errposition(pstate,
exprLocation(list_nth(icolumns,
list_length(exprlist))))));
+ }
/*
* Prepare columns for assignment to target table.
return result;
}
+/*
+ * count_rowexpr_columns -
+ * get number of columns contained in a ROW() expression;
+ * return -1 if expression isn't a RowExpr or a Var referencing one.
+ *
+ * This is currently used only for hint purposes, so we aren't terribly
+ * tense about recognizing all possible cases. The Var case is interesting
+ * because that's what we'll get in the INSERT ... SELECT (...) case.
+ */
+static int
+count_rowexpr_columns(ParseState *pstate, Node *expr)
+{
+ if (expr == NULL)
+ return -1;
+ if (IsA(expr, RowExpr))
+ return list_length(((RowExpr *) expr)->args);
+ if (IsA(expr, Var))
+ {
+ Var *var = (Var *) expr;
+ AttrNumber attnum = var->varattno;
+
+ if (attnum > 0 && var->vartype == RECORDOID)
+ {
+ RangeTblEntry *rte;
+
+ rte = GetRTEByRangeTablePosn(pstate, var->varno, var->varlevelsup);
+ if (rte->rtekind == 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)
+ return -1;
+ expr = (Node *) ste->expr;
+ if (IsA(expr, RowExpr))
+ return list_length(((RowExpr *) expr)->args);
+ }
+ }
+ }
+ return -1;
+}
+
/*
* transformSelectStmt -