From 2c833a728f1f77cbe2a792684dd51ef3447eddad Mon Sep 17 00:00:00 2001
From: "Thomas G. Lockhart" <lockhart@fourpalms.org>
Date: Tue, 23 Dec 1997 19:47:32 +0000
Subject: [PATCH] Implement CREATE TABLE ... AS SELECT borrowing code from
SubSelect and from SELECT ... INTO ... support code. Allow NOT, IS NULL, IS
NOT NULL in constraints. Define unionall boolean flag in SubSelect structure.
Implement row descriptors: (a, b, c) = (x, y, z). Change IS TRUE, IS FALSE,
etc. to expressions using "=" rather than function calls to istrue() or
isfalse() to allow optimization. Force type for TRUE and FALSE to bool.
---
src/backend/parser/gram.y | 276 ++++++++++++++++++++++++++++++++++----
1 file changed, 247 insertions(+), 29 deletions(-)
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 9420627d58c..58cb72f3811 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.79 1997/12/16 15:50:54 thomas Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.80 1997/12/23 19:47:32 thomas Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -63,6 +63,8 @@ extern List *parsetree;
static char *xlateSqlType(char *);
static Node *makeA_Expr(int oper, char *opname, Node *lexpr, Node *rexpr);
+static Node *makeRowExpr(char *opr, List *largs, List *rargs);
+void mapTargetColumns(List *source, List *target);
static List *makeConstantList( A_Const *node);
static char *FlattenStringList(List *list);
static char *fmtId(char *rawid);
@@ -111,7 +113,7 @@ Oid param_type(int t); /* used in parse_expr.c */
%type <node> stmt,
AddAttrStmt, ClosePortalStmt,
- CopyStmt, CreateStmt, CreateSeqStmt, DefineStmt, DestroyStmt,
+ CopyStmt, CreateStmt, CreateAsStmt, CreateSeqStmt, DefineStmt, DestroyStmt,
ExtendStmt, FetchStmt, GrantStmt, CreateTrigStmt, DropTrigStmt,
CreatePLangStmt, DropPLangStmt,
IndexStmt, ListenStmt, OptimizableStmt,
@@ -190,6 +192,10 @@ Oid param_type(int t); /* used in parse_expr.c */
a_expr, a_expr_or_null, AexprConst,
in_expr, in_expr_nodes, not_in_expr, not_in_expr_nodes,
having_clause
+%type <list> row_descriptor, row_list
+%type <node> row_expr
+%type <list> OptCreateAs, CreateAsList
+%type <node> CreateAsElement
%type <value> NumConst
%type <attr> event_object, attr
%type <sortgroupby> groupby
@@ -340,6 +346,7 @@ stmt : AddAttrStmt
| ClosePortalStmt
| CopyStmt
| CreateStmt
+ | CreateAsStmt
| CreateSeqStmt
| CreatePLangStmt
| CreateTrigStmt
@@ -984,10 +991,20 @@ constraint_expr: AexprConst
{ $$ = nconc( $1, lcons( makeString( "AND"), $3)); }
| constraint_expr OR constraint_expr
{ $$ = nconc( $1, lcons( makeString( "OR"), $3)); }
+ | NOT constraint_expr
+ { $$ = lcons( makeString( "NOT"), $2); }
| Op constraint_expr
{ $$ = lcons( makeString( $1), $2); }
| constraint_expr Op
{ $$ = lappend( $1, makeString( $2)); }
+ | constraint_expr ISNULL
+ { $$ = lappend( $1, makeString( "IS NULL")); }
+ | constraint_expr IS NULL_P
+ { $$ = lappend( $1, makeString( "IS NULL")); }
+ | constraint_expr NOTNULL
+ { $$ = lappend( $1, makeString( "IS NOT NULL")); }
+ | constraint_expr IS NOT NULL_P
+ { $$ = lappend( $1, makeString( "IS NOT NULL")); }
| constraint_expr IS TRUE_P
{ $$ = lappend( $1, makeString( "IS TRUE")); }
| constraint_expr IS FALSE_P
@@ -1030,6 +1047,45 @@ OptArchiveType: ARCHIVE '=' NONE { }
| /*EMPTY*/ { }
;
+CreateAsStmt: CREATE TABLE relation_name OptCreateAs AS SubSelect
+ {
+ RetrieveStmt *n = makeNode(RetrieveStmt);
+ SubSelect *s = (SubSelect *)$6;
+ n->unique = s->unique;
+ n->targetList = s->targetList;
+ if ($4 != NIL)
+ mapTargetColumns($4, n->targetList);
+ n->into = $3;
+ n->fromClause = s->fromClause;
+ n->whereClause = s->whereClause;
+ n->groupClause = s->groupClause;
+ n->havingClause = s->havingClause;
+ n->unionClause = NULL;
+ n->sortClause = NULL;
+ $$ = (Node *)n;
+ }
+ ;
+
+OptCreateAs: '(' CreateAsList ')' { $$ = $2; }
+ | /*EMPTY*/ { $$ = NULL; }
+ ;
+
+CreateAsList: CreateAsList ',' CreateAsElement { $$ = lappend($1, $3); }
+ | CreateAsElement { $$ = lcons($1, NIL); }
+ ;
+
+CreateAsElement: ColId
+ {
+ ColumnDef *n = makeNode(ColumnDef);
+ n->colname = $1;
+ n->typename = NULL;
+ n->defval = NULL;
+ n->is_not_null = FALSE;
+ n->constraints = NULL;
+ $$ = (Node *)n;
+ }
+ ;
+
/*****************************************************************************
*
@@ -2227,18 +2283,28 @@ RetrieveStmt: SELECT opt_unique res_target_list2
n->whereClause = $6;
n->groupClause = $7;
n->havingClause = $8;
- n->selectClause = $9;
+ n->unionClause = $9;
n->sortClause = $10;
$$ = (Node *)n;
}
;
-union_clause: UNION opt_union select_list { $$ = $3; }
- | /*EMPTY*/ { $$ = NIL; }
+union_clause: UNION opt_union select_list
+ {
+ SubSelect *n = lfirst($3);
+ n->unionall = $2;
+ $$ = $3;
+ }
+ | /*EMPTY*/
+ { $$ = NIL; }
;
select_list: select_list UNION opt_union SubSelect
- { $$ = lappend($1, $4); }
+ {
+ SubSelect *n = (SubSelect *)$4;
+ n->unionall = $3;
+ $$ = lappend($1, $4);
+ }
| SubSelect
{ $$ = lcons($1, NIL); }
;
@@ -2249,6 +2315,7 @@ SubSelect: SELECT opt_unique res_target_list2
{
SubSelect *n = makeNode(SubSelect);
n->unique = $2;
+ n->unionall = FALSE;
n->targetList = $3;
n->fromClause = $4;
n->whereClause = $5;
@@ -2259,9 +2326,9 @@ SubSelect: SELECT opt_unique res_target_list2
;
result: INTO TABLE relation_name
- { $$= $3; }
+ { $$= $3; }
| /*EMPTY*/
- { $$ = NULL; }
+ { $$ = NULL; }
;
opt_union: ALL { $$ = TRUE; }
@@ -2490,7 +2557,7 @@ relation_expr: relation_name
}
| relation_name '*' %prec '='
{
- /* inheiritance query */
+ /* inheritance query */
$$ = makeNode(RelExpr);
$$->relname = $1;
$$->inh = TRUE;
@@ -2786,12 +2853,61 @@ a_expr_or_null: a_expr
n->val.type = T_Null;
$$ = (Node *)n;
}
+ ;
+
+/* Expressions using row descriptors
+ * Define row_descriptor to allow yacc to break the reduce/reduce conflict
+ * with singleton expressions.
+ */
+row_expr: '(' row_descriptor ')' IN '(' SubSelect ')'
+ {
+ $$ = NULL;
+ }
+ | '(' row_descriptor ')' NOT IN '(' SubSelect ')'
+ {
+ $$ = NULL;
+ }
+ | '(' row_descriptor ')' '=' '(' row_descriptor ')'
+ {
+ $$ = makeRowExpr("=", $2, $6);
+ }
+ | '(' row_descriptor ')' '<' '(' row_descriptor ')'
+ {
+ $$ = makeRowExpr("<", $2, $6);
+ }
+ | '(' row_descriptor ')' '>' '(' row_descriptor ')'
+ {
+ $$ = makeRowExpr("<", $2, $6);
+ }
+ | '(' row_descriptor ')' Op '(' row_descriptor ')'
+ {
+ $$ = makeRowExpr($4, $2, $6);
+ }
+ ;
+
+row_descriptor: row_list ',' a_expr
+ {
+ $$ = lappend($1, $3);
+ }
+ ;
+
+row_list: row_list ',' a_expr
+ {
+ $$ = lappend($1, $3);
+ }
+ | a_expr
+ {
+ $$ = lcons($1, NIL);
+ }
+ ;
a_expr: attr opt_indirection
{
$1->indirection = $2;
$$ = (Node *)$1;
}
+ | row_expr
+ { $$ = $1; }
| AexprConst
{ $$ = $1; }
| '-' a_expr %prec UMINUS
@@ -3052,33 +3168,46 @@ a_expr: attr opt_indirection
{ $$ = makeA_Expr(NOTNULL, NULL, $1, NULL); }
| a_expr IS NOT NULL_P
{ $$ = makeA_Expr(NOTNULL, NULL, $1, NULL); }
+ /* IS TRUE, IS FALSE, etc used to be function calls
+ * but let's make them expressions to allow the optimizer
+ * a chance to eliminate them if a_expr is a constant string.
+ * - thomas 1997-12-22
+ */
| a_expr IS TRUE_P
{
- FuncCall *n = makeNode(FuncCall);
- n->funcname = "istrue";
- n->args = lcons($1,NIL);
- $$ = (Node *)n;
+ A_Const *n = makeNode(A_Const);
+ n->val.type = T_String;
+ n->val.val.str = "t";
+ n->typename = makeNode(TypeName);
+ n->typename->name = xlateSqlType("bool");
+ $$ = makeA_Expr(OP, "=", $1,(Node *)n);
}
- | a_expr IS FALSE_P
+ | a_expr IS NOT FALSE_P
{
- FuncCall *n = makeNode(FuncCall);
- n->funcname = "isfalse";
- n->args = lcons($1,NIL);
- $$ = (Node *)n;
+ A_Const *n = makeNode(A_Const);
+ n->val.type = T_String;
+ n->val.val.str = "t";
+ n->typename = makeNode(TypeName);
+ n->typename->name = xlateSqlType("bool");
+ $$ = makeA_Expr(OP, "=", $1,(Node *)n);
}
- | a_expr IS NOT TRUE_P
+ | a_expr IS FALSE_P
{
- FuncCall *n = makeNode(FuncCall);
- n->funcname = "isfalse";
- n->args = lcons($1,NIL);
- $$ = (Node *)n;
+ A_Const *n = makeNode(A_Const);
+ n->val.type = T_String;
+ n->val.val.str = "f";
+ n->typename = makeNode(TypeName);
+ n->typename->name = xlateSqlType("bool");
+ $$ = makeA_Expr(OP, "=", $1,(Node *)n);
}
- | a_expr IS NOT FALSE_P
+ | a_expr IS NOT TRUE_P
{
- FuncCall *n = makeNode(FuncCall);
- n->funcname = "istrue";
- n->args = lcons($1,NIL);
- $$ = (Node *)n;
+ A_Const *n = makeNode(A_Const);
+ n->val.type = T_String;
+ n->val.val.str = "f";
+ n->typename = makeNode(TypeName);
+ n->typename->name = xlateSqlType("bool");
+ $$ = makeA_Expr(OP, "=", $1,(Node *)n);
}
| a_expr BETWEEN AexprConst AND AexprConst
{
@@ -3547,6 +3676,8 @@ AexprConst: Iconst
A_Const *n = makeNode(A_Const);
n->val.type = T_String;
n->val.val.str = "t";
+ n->typename = makeNode(TypeName);
+ n->typename->name = xlateSqlType("bool");
$$ = (Node *)n;
}
| FALSE_P
@@ -3554,6 +3685,8 @@ AexprConst: Iconst
A_Const *n = makeNode(A_Const);
n->val.type = T_String;
n->val.val.str = "f";
+ n->typename = makeNode(TypeName);
+ n->typename->name = xlateSqlType("bool");
$$ = (Node *)n;
}
;
@@ -3654,7 +3787,8 @@ SpecialRuleRelation: CURRENT
%%
-static Node *makeA_Expr(int oper, char *opname, Node *lexpr, Node *rexpr)
+static Node *
+makeA_Expr(int oper, char *opname, Node *lexpr, Node *rexpr)
{
A_Expr *a = makeNode(A_Expr);
a->oper = oper;
@@ -3664,6 +3798,90 @@ static Node *makeA_Expr(int oper, char *opname, Node *lexpr, Node *rexpr)
return (Node *)a;
}
+/* makeRowExpr()
+ * Generate separate operator nodes for a single row descriptor expression.
+ * Perhaps this should go deeper in the parser someday... - thomas 1997-12-22
+ */
+static Node *
+makeRowExpr(char *opr, List *largs, List *rargs)
+{
+ Node *expr = NULL;
+ Node *larg, *rarg;
+
+ if (length(largs) != length(rargs))
+ elog(WARN,"Unequal number of entries in row expression",NULL);
+
+ if (lnext(largs) != NIL)
+ expr = makeRowExpr(opr,lnext(largs),lnext(rargs));
+
+ larg = lfirst(largs);
+ rarg = lfirst(rargs);
+
+ if ((strcmp(opr, "=") == 0)
+ || (strcmp(opr, "<") == 0)
+ || (strcmp(opr, "<=") == 0)
+ || (strcmp(opr, ">") == 0)
+ || (strcmp(opr, ">=") == 0))
+ {
+ if (expr == NULL)
+ expr = makeA_Expr(OP, opr, larg, rarg);
+ else
+ expr = makeA_Expr(AND, NULL, expr, makeA_Expr(OP, opr, larg, rarg));
+ }
+ else if (strcmp(opr, "<>") == 0)
+ {
+ if (expr == NULL)
+ expr = makeA_Expr(OP, opr, larg, rarg);
+ else
+ expr = makeA_Expr(OR, NULL, expr, makeA_Expr(OP, opr, larg, rarg));
+ }
+ else
+ {
+ elog(WARN,"Operator '%s' not implemented for row expressions",opr);
+ }
+
+#if FALSE
+ while ((largs != NIL) && (rargs != NIL))
+ {
+ larg = lfirst(largs);
+ rarg = lfirst(rargs);
+
+ if (expr == NULL)
+ expr = makeA_Expr(OP, opr, larg, rarg);
+ else
+ expr = makeA_Expr(AND, NULL, expr, makeA_Expr(OP, opr, larg, rarg));
+
+ largs = lnext(largs);
+ rargs = lnext(rargs);
+ }
+ pprint(expr);
+#endif
+
+ return expr;
+} /* makeRowExpr() */
+
+void
+mapTargetColumns(List *src, List *dst)
+{
+ ColumnDef *s;
+ ResTarget *d;
+
+ if (length(src) != length(dst))
+ elog(WARN,"CREATE TABLE/AS SELECT has mismatched column count",NULL);
+
+ while ((src != NIL) && (dst != NIL))
+ {
+ s = (ColumnDef *)lfirst(src);
+ d = (ResTarget *)lfirst(dst);
+
+ d->name = s->colname;
+
+ src = lnext(src);
+ dst = lnext(dst);
+ }
+
+ return;
+} /* mapTargetColumns() */
static Node *makeIndexable(char *opname, Node *lexpr, Node *rexpr)
{
--
GitLab