*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.103 1998/02/03 19:26:41 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.104 1998/02/04 06:11:46 thomas Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
%type <node> columnDef, alter_clause
%type <defelt> def_elem
%type <node> def_arg, columnElem, where_clause,
- a_expr, a_expr_or_null, AexprConst,
+ a_expr, a_expr_or_null, b_expr, AexprConst,
in_expr, in_expr_nodes, not_in_expr, not_in_expr_nodes,
having_clause
%type <list> row_descriptor, row_list
%token TYPE_P
/* Keywords for Postgres support (not in SQL92 reserved words) */
-%token ABORT_TRANS, ACL, AFTER, AGGREGATE, ANALYZE,
- APPEND, BACKWARD, BEFORE, BINARY, CLUSTER, COPY,
+%token ABORT_TRANS, AFTER, AGGREGATE, ANALYZE,
+ BACKWARD, BEFORE, BINARY, CLUSTER, COPY,
DATABASE, DELIMITERS, DO, EXPLAIN, EXTEND,
FORWARD, FUNCTION, HANDLER,
INDEX, INHERITS, INSTEAD, ISNULL,
- LANCOMPILER, LISTEN, LOAD, LOCK_P, LOCATION, MERGE, MOVE,
+ LANCOMPILER, LISTEN, LOAD, LOCK_P, LOCATION, MOVE,
NEW, NONE, NOTHING, NOTNULL, OIDS, OPERATOR, PROCEDURAL,
- RECIPE, RENAME, REPLACE, RESET, RETURNS, RULE,
+ RECIPE, RENAME, RESET, RETURNS, RULE,
SEQUENCE, SETOF, SHOW, STDIN, STDOUT, TRUSTED,
VACUUM, VERBOSE, VERSION
}
;
+/*
+ * This is the heart of the expression syntax.
+ * Note that the BETWEEN clause looks similar to a boolean expression
+ * and so we must define b_expr which is almost the same as a_expr
+ * but without the boolean expressions.
+ * All operations are allowed in a BETWEEN clause if surrounded by parens.
+ */
+
a_expr: attr opt_indirection
{
$1->indirection = $2;
{ $$ = $1; }
| AexprConst
{ $$ = $1; }
+ | ColId
+ {
+ /* could be a column name or a relation_name */
+ Ident *n = makeNode(Ident);
+ n->name = $1;
+ n->indirection = NULL;
+ $$ = (Node *)n;
+ }
| '-' a_expr %prec UMINUS
{ $$ = makeA_Expr(OP, "-", NULL, $2); }
| a_expr '+' a_expr
{ $$ = makeA_Expr(OP, $1, NULL, $2); }
| a_expr Op
{ $$ = makeA_Expr(OP, $2, $1, NULL); }
- | ColId
- {
- /* could be a column name or a relation_name */
- Ident *n = makeNode(Ident);
- n->name = $1;
- n->indirection = NULL;
- $$ = (Node *)n;
- }
| name '(' '*' ')'
{
/* cheap hack for aggregate (eg. count) */
n->typename->name = xlateSqlType("bool");
$$ = makeA_Expr(OP, "=", $1,(Node *)n);
}
- | a_expr BETWEEN AexprConst AND AexprConst
+ | a_expr BETWEEN b_expr AND b_expr
{
$$ = makeA_Expr(AND, NULL,
makeA_Expr(OP, ">=", $1, $3),
makeA_Expr(OP, "<=", $1, $5));
}
- | a_expr NOT BETWEEN AexprConst AND AexprConst
+ | a_expr NOT BETWEEN b_expr AND b_expr
{
$$ = makeA_Expr(OR, NULL,
makeA_Expr(OP, "<", $1, $4),
{ $$ = makeA_Expr(NOT, NULL, NULL, $2); }
;
+/*
+ * b_expr is a subset of the complete expression syntax
+ * defined by a_expr. b_expr is used in BETWEEN clauses
+ * to eliminate parser ambiguities stemming from the AND keyword.
+ */
+
+b_expr: attr opt_indirection
+ {
+ $1->indirection = $2;
+ $$ = (Node *)$1;
+ }
+ | AexprConst
+ { $$ = $1; }
+ | ColId
+ {
+ /* could be a column name or a relation_name */
+ Ident *n = makeNode(Ident);
+ n->name = $1;
+ n->indirection = NULL;
+ $$ = (Node *)n;
+ }
+ | '-' b_expr %prec UMINUS
+ { $$ = makeA_Expr(OP, "-", NULL, $2); }
+ | b_expr '+' b_expr
+ { $$ = makeA_Expr(OP, "+", $1, $3); }
+ | b_expr '-' b_expr
+ { $$ = makeA_Expr(OP, "-", $1, $3); }
+ | b_expr '/' b_expr
+ { $$ = makeA_Expr(OP, "/", $1, $3); }
+ | b_expr '*' b_expr
+ { $$ = makeA_Expr(OP, "*", $1, $3); }
+ | ':' b_expr
+ { $$ = makeA_Expr(OP, ":", NULL, $2); }
+ | ';' b_expr
+ { $$ = makeA_Expr(OP, ";", NULL, $2); }
+ | '|' b_expr
+ { $$ = makeA_Expr(OP, "|", NULL, $2); }
+ | b_expr TYPECAST Typename
+ {
+ $$ = (Node *)$1;
+ /* AexprConst can be either A_Const or ParamNo */
+ if (nodeTag($1) == T_A_Const) {
+ ((A_Const *)$1)->typename = $3;
+ } else if (nodeTag($1) == T_Param) {
+ ((ParamNo *)$1)->typename = $3;
+ /* otherwise, try to transform to a function call */
+ } else {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = $3->name;
+ n->args = lcons($1,NIL);
+ $$ = (Node *)n;
+ }
+ }
+ | CAST b_expr AS Typename
+ {
+ $$ = (Node *)$2;
+ /* AexprConst can be either A_Const or ParamNo */
+ if (nodeTag($2) == T_A_Const) {
+ ((A_Const *)$2)->typename = $4;
+ } else if (nodeTag($2) == T_Param) {
+ ((ParamNo *)$2)->typename = $4;
+ /* otherwise, try to transform to a function call */
+ } else {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = $4->name;
+ n->args = lcons($2,NIL);
+ $$ = (Node *)n;
+ }
+ }
+ | '(' a_expr ')'
+ { $$ = $2; }
+ | b_expr Op b_expr
+ { $$ = makeIndexable($2,$1,$3); }
+ | Op b_expr
+ { $$ = makeA_Expr(OP, $1, NULL, $2); }
+ | b_expr Op
+ { $$ = makeA_Expr(OP, $2, $1, NULL); }
+ | name '(' ')'
+ {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = $1;
+ n->args = NIL;
+ $$ = (Node *)n;
+ }
+ | name '(' expr_list ')'
+ {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = $1;
+ n->args = $3;
+ $$ = (Node *)n;
+ }
+ | CURRENT_DATE
+ {
+ A_Const *n = makeNode(A_Const);
+ TypeName *t = makeNode(TypeName);
+
+ n->val.type = T_String;
+ n->val.val.str = "now";
+ n->typename = t;
+
+ t->name = xlateSqlType("date");
+ t->setof = FALSE;
+
+ $$ = (Node *)n;
+ }
+ | CURRENT_TIME
+ {
+ A_Const *n = makeNode(A_Const);
+ TypeName *t = makeNode(TypeName);
+
+ n->val.type = T_String;
+ n->val.val.str = "now";
+ n->typename = t;
+
+ t->name = xlateSqlType("time");
+ t->setof = FALSE;
+
+ $$ = (Node *)n;
+ }
+ | CURRENT_TIME '(' Iconst ')'
+ {
+ FuncCall *n = makeNode(FuncCall);
+ A_Const *s = makeNode(A_Const);
+ TypeName *t = makeNode(TypeName);
+
+ n->funcname = xlateSqlType("time");
+ n->args = lcons(s, NIL);
+
+ s->val.type = T_String;
+ s->val.val.str = "now";
+ s->typename = t;
+
+ t->name = xlateSqlType("time");
+ t->setof = FALSE;
+
+ if ($3 != 0)
+ elog(NOTICE,"CURRENT_TIME(%d) precision not implemented; zero used instead",$3);
+
+ $$ = (Node *)n;
+ }
+ | CURRENT_TIMESTAMP
+ {
+ A_Const *n = makeNode(A_Const);
+ TypeName *t = makeNode(TypeName);
+
+ n->val.type = T_String;
+ n->val.val.str = "now";
+ n->typename = t;
+
+ t->name = xlateSqlType("timestamp");
+ t->setof = FALSE;
+
+ $$ = (Node *)n;
+ }
+ | CURRENT_TIMESTAMP '(' Iconst ')'
+ {
+ FuncCall *n = makeNode(FuncCall);
+ A_Const *s = makeNode(A_Const);
+ TypeName *t = makeNode(TypeName);
+
+ n->funcname = xlateSqlType("timestamp");
+ n->args = lcons(s, NIL);
+
+ s->val.type = T_String;
+ s->val.val.str = "now";
+ s->typename = t;
+
+ t->name = xlateSqlType("timestamp");
+ t->setof = FALSE;
+
+ if ($3 != 0)
+ elog(NOTICE,"CURRENT_TIMESTAMP(%d) precision not implemented; zero used instead",$3);
+
+ $$ = (Node *)n;
+ }
+ | CURRENT_USER
+ {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = "getpgusername";
+ n->args = NIL;
+ $$ = (Node *)n;
+ }
+ | POSITION '(' position_list ')'
+ {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = "strpos";
+ n->args = $3;
+ $$ = (Node *)n;
+ }
+ | SUBSTRING '(' substr_list ')'
+ {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = "substr";
+ n->args = $3;
+ $$ = (Node *)n;
+ }
+ /* various trim expressions are defined in SQL92 - thomas 1997-07-19 */
+ | TRIM '(' BOTH trim_list ')'
+ {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = "btrim";
+ n->args = $4;
+ $$ = (Node *)n;
+ }
+ | TRIM '(' LEADING trim_list ')'
+ {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = "ltrim";
+ n->args = $4;
+ $$ = (Node *)n;
+ }
+ | TRIM '(' TRAILING trim_list ')'
+ {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = "rtrim";
+ n->args = $4;
+ $$ = (Node *)n;
+ }
+ | TRIM '(' trim_list ')'
+ {
+ FuncCall *n = makeNode(FuncCall);
+ n->funcname = "btrim";
+ n->args = $3;
+ $$ = (Node *)n;
+ }
+ ;
+
opt_indirection: '[' a_expr ']' opt_indirection
{
A_Indices *ai = makeNode(A_Indices);
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