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-rw-r--r--src/backend/parser/gram.y301
1 files changed, 214 insertions, 87 deletions
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index f73b4552b84..410caf72e0a 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.335 2002/07/01 15:27:55 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.336 2002/07/04 15:23:59 thomas Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -90,7 +90,11 @@ static Node *makeIntConst(int val);
static Node *makeFloatConst(char *str);
static Node *makeAConst(Value *v);
static Node *makeRowExpr(List *opr, List *largs, List *rargs);
+static Node *makeDistinctExpr(List *largs, List *rargs);
+static Node *makeRowNullTest(NullTestType test, List *args);
static DefElem *makeDefElem(char *name, Node *arg);
+static A_Const *makeBoolConst(bool state);
+static FuncCall *makeOverlaps(List *largs, List *rargs);
static SelectStmt *findLeftmostSelect(SelectStmt *node);
static void insertSelectOptions(SelectStmt *stmt,
List *sortClause, List *forUpdate,
@@ -265,10 +269,9 @@ static void doNegateFloat(Value *v);
%type <node> columnDef
%type <defelt> def_elem
%type <node> def_arg, columnElem, where_clause, insert_column_item,
- a_expr, b_expr, c_expr, AexprConst,
+ a_expr, b_expr, c_expr, r_expr, AexprConst,
in_expr, having_clause, func_table
-%type <list> row_descriptor, row_list, in_expr_nodes
-%type <node> row_expr
+%type <list> row, row_descriptor, row_list, in_expr_nodes
%type <node> case_expr, case_arg, when_clause, case_default
%type <list> when_clause_list
%type <ival> sub_type
@@ -386,7 +389,7 @@ static void doNegateFloat(Value *v);
SYSID,
TABLE, TEMP, TEMPLATE, TEMPORARY, THEN, TIME, TIMESTAMP,
- TO, TOAST, TRAILING, TRANSACTION, TRIGGER, TRIM, TRUE_P,
+ TO, TOAST, TRAILING, TRANSACTION, TREAT, TRIGGER, TRIM, TRUE_P,
TRUNCATE, TRUSTED, TYPE_P,
UNENCRYPTED, UNION, UNIQUE, UNKNOWN, UNLISTEN, UNTIL,
@@ -426,7 +429,7 @@ static void doNegateFloat(Value *v);
%nonassoc LIKE ILIKE SIMILAR
%nonassoc ESCAPE
%nonassoc OVERLAPS
-%nonassoc BETWEEN
+%nonassoc BETWEEN DISTINCT
%nonassoc IN_P
%left POSTFIXOP /* dummy for postfix Op rules */
%left Op OPERATOR /* multi-character ops and user-defined operators */
@@ -5072,84 +5075,115 @@ opt_interval:
/* Expressions using row descriptors
* Define row_descriptor to allow yacc to break the reduce/reduce conflict
- * with singleton expressions.
+ * with singleton expressions. Use SQL99's ROW keyword to allow rows of
+ * one element.
*/
-row_expr: '(' row_descriptor ')' IN_P select_with_parens
+r_expr: row IN_P select_with_parens
{
SubLink *n = makeNode(SubLink);
- n->lefthand = $2;
+ n->lefthand = $1;
n->oper = (List *) makeSimpleA_Expr(OP, "=", NULL, NULL);
n->useor = FALSE;
n->subLinkType = ANY_SUBLINK;
- n->subselect = $5;
+ n->subselect = $3;
$$ = (Node *)n;
}
- | '(' row_descriptor ')' NOT IN_P select_with_parens
+ | row NOT IN_P select_with_parens
{
SubLink *n = makeNode(SubLink);
- n->lefthand = $2;
+ n->lefthand = $1;
n->oper = (List *) makeSimpleA_Expr(OP, "<>", NULL, NULL);
n->useor = TRUE;
n->subLinkType = ALL_SUBLINK;
- n->subselect = $6;
+ n->subselect = $4;
$$ = (Node *)n;
}
- | '(' row_descriptor ')' qual_all_Op sub_type select_with_parens
+ | row qual_all_Op sub_type select_with_parens
%prec Op
{
SubLink *n = makeNode(SubLink);
- n->lefthand = $2;
- n->oper = (List *) makeA_Expr(OP, $4, NULL, NULL);
- if (strcmp(strVal(llast($4)), "<>") == 0)
+ n->lefthand = $1;
+ n->oper = (List *) makeA_Expr(OP, $2, NULL, NULL);
+ if (strcmp(strVal(llast($2)), "<>") == 0)
n->useor = TRUE;
else
n->useor = FALSE;
- n->subLinkType = $5;
- n->subselect = $6;
+ n->subLinkType = $3;
+ n->subselect = $4;
$$ = (Node *)n;
}
- | '(' row_descriptor ')' qual_all_Op select_with_parens
+ | row qual_all_Op select_with_parens
%prec Op
{
SubLink *n = makeNode(SubLink);
- n->lefthand = $2;
- n->oper = (List *) makeA_Expr(OP, $4, NULL, NULL);
- if (strcmp(strVal(llast($4)), "<>") == 0)
+ n->lefthand = $1;
+ n->oper = (List *) makeA_Expr(OP, $2, NULL, NULL);
+ if (strcmp(strVal(llast($2)), "<>") == 0)
n->useor = TRUE;
else
n->useor = FALSE;
n->subLinkType = MULTIEXPR_SUBLINK;
- n->subselect = $5;
+ n->subselect = $3;
$$ = (Node *)n;
}
- | '(' row_descriptor ')' qual_all_Op '(' row_descriptor ')'
+ | row qual_all_Op row
%prec Op
{
- $$ = makeRowExpr($4, $2, $6);
+ $$ = makeRowExpr($2, $1, $3);
}
- | '(' row_descriptor ')' OVERLAPS '(' row_descriptor ')'
+ | row IS NULL_P
{
- FuncCall *n = makeNode(FuncCall);
- List *largs = $2;
- List *rargs = $6;
- n->funcname = SystemFuncName("overlaps");
- if (length(largs) == 1)
- largs = lappend(largs, $2);
- else if (length(largs) != 2)
- elog(ERROR, "Wrong number of parameters"
- " on left side of OVERLAPS expression");
- if (length(rargs) == 1)
- rargs = lappend(rargs, $6);
- else if (length(rargs) != 2)
- elog(ERROR, "Wrong number of parameters"
- " on right side of OVERLAPS expression");
- n->args = nconc(largs, rargs);
- n->agg_star = FALSE;
- n->agg_distinct = FALSE;
- $$ = (Node *)n;
+ $$ = makeRowNullTest(IS_NULL, $1);
+ }
+ | row IS NOT NULL_P
+ {
+ $$ = makeRowNullTest(IS_NOT_NULL, $1);
+ }
+ | row OVERLAPS row
+ {
+ $$ = (Node *)makeOverlaps($1, $3);
+ }
+ | row IS DISTINCT FROM row
+ {
+ /* IS DISTINCT FROM has the following rules for non-array types:
+ * a) the row lengths must be equal
+ * b) if both rows are zero-length, then they are not distinct
+ * c) if any element is distinct, the rows are distinct
+ * The rules for an element being distinct:
+ * a) if the elements are both NULL, then they are not distinct
+ * b) if the elements compare to be equal, then they are not distinct
+ * c) otherwise, they are distinct
+ */
+ List *largs = $1;
+ List *rargs = $5;
+ /* lengths don't match? then complain */
+ if (length(largs) != length(rargs))
+ {
+ elog(ERROR, "Unequal number of entries in row expression");
+ }
+ /* both are zero-length rows? then they are not distinct */
+ else if (length(largs) <= 0)
+ {
+ $$ = (Node *)makeBoolConst(FALSE);
+ }
+ /* otherwise, we need to compare each element */
+ else
+ {
+ $$ = (Node *)makeDistinctExpr(largs, rargs);
+ }
}
;
+/* Explicit row production.
+ * SQL99 allows an optional ROW keyword, so we can now do single-element productions
+ * without conflicting with the parenthesized a_expr production.
+ */
+row: ROW '(' row_descriptor ')' { $$ = $3; }
+ | ROW '(' a_expr ')' { $$ = makeList1($3); }
+ | ROW '(' ')' { $$ = NULL; }
+ | '(' row_descriptor ')' { $$ = $2; }
+;
+
row_descriptor:
row_list ',' a_expr { $$ = lappend($1, $3); }
;
@@ -5356,8 +5390,6 @@ a_expr: c_expr { $$ = $1; }
* Allow two SQL extensions
* a ISNULL
* a NOTNULL
- * NOTE: this is not yet fully SQL-compatible, since SQL92
- * allows a row constructor as argument, not just a scalar.
*/
| a_expr ISNULL
{
@@ -5387,15 +5419,6 @@ a_expr: c_expr { $$ = $1; }
n->nulltesttype = IS_NOT_NULL;
$$ = (Node *)n;
}
- /* 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
- *
- * Created BooleanTest Node type, and changed handling
- * for NULL inputs
- * - jec 2001-06-18
- */
| a_expr IS TRUE_P
{
BooleanTest *b = makeNode(BooleanTest);
@@ -5438,6 +5461,8 @@ a_expr: c_expr { $$ = $1; }
b->booltesttype = IS_NOT_UNKNOWN;
$$ = (Node *)b;
}
+ | a_expr IS DISTINCT FROM a_expr %prec DISTINCT
+ { $$ = (Node *) makeSimpleA_Expr(DISTINCT, "=", $1, $5); }
| a_expr BETWEEN b_expr AND b_expr %prec BETWEEN
{
$$ = (Node *) makeA_Expr(AND, NIL,
@@ -5457,8 +5482,7 @@ a_expr: c_expr { $$ = $1; }
{
SubLink *n = (SubLink *)$3;
n->lefthand = makeList1($1);
- n->oper = (List *) makeSimpleA_Expr(OP, "=",
- NULL, NULL);
+ n->oper = (List *) makeSimpleA_Expr(OP, "=", NULL, NULL);
n->useor = FALSE;
n->subLinkType = ANY_SUBLINK;
$$ = (Node *)n;
@@ -5470,8 +5494,7 @@ a_expr: c_expr { $$ = $1; }
foreach(l, (List *) $3)
{
Node *cmp;
- cmp = (Node *) makeSimpleA_Expr(OP, "=",
- $1, lfirst(l));
+ cmp = (Node *) makeSimpleA_Expr(OP, "=", $1, lfirst(l));
if (n == NULL)
n = cmp;
else
@@ -5487,8 +5510,7 @@ a_expr: c_expr { $$ = $1; }
{
SubLink *n = (SubLink *)$4;
n->lefthand = makeList1($1);
- n->oper = (List *) makeSimpleA_Expr(OP, "<>",
- NULL, NULL);
+ n->oper = (List *) makeSimpleA_Expr(OP, "<>", NULL, NULL);
n->useor = FALSE;
n->subLinkType = ALL_SUBLINK;
$$ = (Node *)n;
@@ -5500,8 +5522,7 @@ a_expr: c_expr { $$ = $1; }
foreach(l, (List *) $4)
{
Node *cmp;
- cmp = (Node *) makeSimpleA_Expr(OP, "<>",
- $1, lfirst(l));
+ cmp = (Node *) makeSimpleA_Expr(OP, "<>", $1, lfirst(l));
if (n == NULL)
n = cmp;
else
@@ -5520,7 +5541,7 @@ a_expr: c_expr { $$ = $1; }
n->subselect = $4;
$$ = (Node *)n;
}
- | row_expr
+ | r_expr
{ $$ = $1; }
;
@@ -5573,6 +5594,8 @@ b_expr: c_expr
{ $$ = (Node *) makeA_Expr(OP, $1, NULL, $2); }
| b_expr qual_Op %prec POSTFIXOP
{ $$ = (Node *) makeA_Expr(OP, $2, $1, NULL); }
+ | b_expr IS DISTINCT FROM b_expr %prec Op
+ { $$ = (Node *) makeSimpleA_Expr(DISTINCT, "=", $1, $5); }
;
/*
@@ -5606,8 +5629,6 @@ c_expr: columnref { $$ = (Node *) $1; }
n->indirection = $5;
$$ = (Node *)n;
}
- | CAST '(' a_expr AS Typename ')'
- { $$ = makeTypeCast($3, $5); }
| case_expr
{ $$ = $1; }
| func_name '(' ')'
@@ -5908,6 +5929,8 @@ c_expr: columnref { $$ = (Node *) $1; }
n->agg_distinct = FALSE;
$$ = (Node *)n;
}
+ | CAST '(' a_expr AS Typename ')'
+ { $$ = makeTypeCast($3, $5); }
| EXTRACT '(' extract_list ')'
{
FuncCall *n = makeNode(FuncCall);
@@ -5953,6 +5976,22 @@ c_expr: columnref { $$ = (Node *) $1; }
n->agg_distinct = FALSE;
$$ = (Node *)n;
}
+ | TREAT '(' a_expr AS Typename ')'
+ {
+ /* TREAT(expr AS target) converts expr of a particular type to target,
+ * which is defined to be a subtype of the original expression.
+ * In SQL99, this is intended for use with structured UDTs,
+ * but let's make this a generally useful form allowing stronger
+ * coersions than are handled by implicit casting.
+ */
+ FuncCall *n = makeNode(FuncCall);
+ /* Convert SystemTypeName() to SystemFuncName() even though
+ * at the moment they result in the same thing.
+ */
+ n->funcname = SystemFuncName(((Value *)llast($5->names))->val.str);
+ n->args = makeList1($3);
+ $$ = (Node *)n;
+ }
| TRIM '(' BOTH trim_list ')'
{
/* various trim expressions are defined in SQL92
@@ -6505,19 +6544,11 @@ AexprConst: Iconst
}
| TRUE_P
{
- A_Const *n = makeNode(A_Const);
- n->val.type = T_String;
- n->val.val.str = "t";
- n->typename = SystemTypeName("bool");
- $$ = (Node *)n;
+ $$ = (Node *)makeBoolConst(TRUE);
}
| FALSE_P
{
- A_Const *n = makeNode(A_Const);
- n->val.type = T_String;
- n->val.val.str = "f";
- n->typename = SystemTypeName("bool");
- $$ = (Node *)n;
+ $$ = (Node *)makeBoolConst(FALSE);
}
| NULL_P
{
@@ -6707,7 +6738,6 @@ unreserved_keyword:
| RETURNS
| REVOKE
| ROLLBACK
- | ROW
| RULE
| SCHEMA
| SCROLL
@@ -6792,6 +6822,7 @@ col_name_keyword:
| OVERLAY
| POSITION
| REAL
+ | ROW
| SETOF
| SMALLINT
| SUBSTRING
@@ -6903,6 +6934,7 @@ reserved_keyword:
| THEN
| TO
| TRAILING
+ | TREAT
| TRUE_P
| UNION
| UNIQUE
@@ -7028,6 +7060,19 @@ makeDefElem(char *name, Node *arg)
return f;
}
+/* makeBoolConst()
+ * Create an A_Const node and initialize to a boolean constant.
+ */
+static A_Const *
+makeBoolConst(bool state)
+{
+ A_Const *n = makeNode(A_Const);
+ n->val.type = T_String;
+ n->val.val.str = (state? "t": "f");
+ n->typename = SystemTypeName("bool");
+ return n;
+}
+
/* makeRowExpr()
* Generate separate operator nodes for a single row descriptor expression.
* Perhaps this should go deeper in the parser someday...
@@ -7082,8 +7127,90 @@ makeRowExpr(List *opr, List *largs, List *rargs)
return expr;
}
+/* makeDistinctExpr()
+ * Generate separate operator nodes for a single row descriptor expression.
+ * Same comments as for makeRowExpr().
+ */
+static Node *
+makeDistinctExpr(List *largs, List *rargs)
+{
+ Node *expr = NULL;
+ Node *larg, *rarg;
+
+ if (length(largs) != length(rargs))
+ elog(ERROR, "Unequal number of entries in row expression");
+
+ if (lnext(largs) != NIL)
+ expr = makeDistinctExpr(lnext(largs), lnext(rargs));
+
+ larg = lfirst(largs);
+ rarg = lfirst(rargs);
+
+ if (expr == NULL)
+ expr = (Node *) makeSimpleA_Expr(DISTINCT, "=", larg, rarg);
+ else
+ expr = (Node *) makeA_Expr(OR, NIL, expr,
+ (Node *) makeSimpleA_Expr(DISTINCT, "=",
+ larg, rarg));
+
+ return expr;
+}
+
+/* makeRowNullTest()
+ * Generate separate operator nodes for a single row descriptor test.
+ */
+static Node *
+makeRowNullTest(NullTestType test, List *args)
+{
+ Node *expr = NULL;
+ Node *arg;
+ NullTest *n;
+
+ if (lnext(args) != NIL)
+ expr = makeRowNullTest(test, lnext(args));
+
+ arg = lfirst(args);
+
+ n = makeNode(NullTest);
+ n->arg = arg;
+ n->nulltesttype = test;
+
+ if (expr == NULL)
+ expr = (Node *)n;
+ else if (test == IS_NOT_NULL)
+ expr = (Node *) makeA_Expr(OR, NIL, expr, (Node *)n);
+ else
+ expr = (Node *) makeA_Expr(AND, NIL, expr, (Node *)n);
+
+ return expr;
+}
+
+/* makeOverlaps()
+ * Create and populate a FuncCall node to support the OVERLAPS operator.
+ */
+static FuncCall *
+makeOverlaps(List *largs, List *rargs)
+{
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = SystemFuncName("overlaps");
+ if (length(largs) == 1)
+ largs = lappend(largs, largs);
+ else if (length(largs) != 2)
+ elog(ERROR, "Wrong number of parameters"
+ " on left side of OVERLAPS expression");
+ if (length(rargs) == 1)
+ rargs = lappend(rargs, rargs);
+ else if (length(rargs) != 2)
+ elog(ERROR, "Wrong number of parameters"
+ " on right side of OVERLAPS expression");
+ n->args = nconc(largs, rargs);
+ n->agg_star = FALSE;
+ n->agg_distinct = FALSE;
+ return n;
+}
+
/* findLeftmostSelect()
- * Find the leftmost component SelectStmt in a set-operation parsetree.
+ * Find the leftmost component SelectStmt in a set-operation parsetree.
*/
static SelectStmt *
findLeftmostSelect(SelectStmt *node)
@@ -7095,7 +7222,7 @@ findLeftmostSelect(SelectStmt *node)
}
/* insertSelectOptions()
- * Insert ORDER BY, etc into an already-constructed SelectStmt.
+ * Insert ORDER BY, etc into an already-constructed SelectStmt.
*
* This routine is just to avoid duplicating code in SelectStmt productions.
*/
@@ -7147,7 +7274,7 @@ makeSetOp(SetOperation op, bool all, Node *larg, Node *rarg)
}
/* SystemFuncName()
- * Build a properly-qualified reference to a built-in function.
+ * Build a properly-qualified reference to a built-in function.
*/
List *
SystemFuncName(char *name)
@@ -7156,7 +7283,7 @@ SystemFuncName(char *name)
}
/* SystemTypeName()
- * Build a properly-qualified reference to a built-in type.
+ * Build a properly-qualified reference to a built-in type.
*
* typmod is defaulted, but may be changed afterwards by caller.
*/
@@ -7170,7 +7297,7 @@ SystemTypeName(char *name)
return n;
}
-/*
+/* parser_init()
* Initialize to parse one query string
*/
void
@@ -7185,7 +7312,7 @@ parser_init(Oid *typev, int nargs)
pfunc_num_args = nargs;
}
-/*
+/* param_type()
* Fetch a parameter type previously passed to parser_init
*/
Oid
@@ -7196,7 +7323,7 @@ param_type(int t)
return param_type_info[t - 1];
}
-/*
+/* exprIsNullConstant()
* Test whether an a_expr is a plain NULL constant or not.
*/
bool
@@ -7213,8 +7340,8 @@ exprIsNullConstant(Node *arg)
return FALSE;
}
-/*
- * doNegate --- handle negation of a numeric constant.
+/* doNegate()
+ * Handle negation of a numeric constant.
*
* Formerly, we did this here because the optimizer couldn't cope with
* indexquals that looked like "var = -4" --- it wants "var = const"
generated by cgit v1.2.3 (git 2.25.1) at 2025-08-08 06:32:58 +0000