*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.60 1997/10/30 16:39:27 thomas Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.61 1997/10/31 00:50:39 momjian Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
static List *makeConstantList( A_Const *node);
static char *FlattenStringList(List *list);
static char *fmtId(char *rawid);
+static Node *makeIndexable(char *opname, Node *lexpr, Node *rexpr);
/* old versions of flex define this as a macro */
#if defined(yywrap)
| '(' a_expr_or_null ')'
{ $$ = $2; }
| a_expr Op a_expr
- { $$ = makeA_Expr(OP, $2, $1, $3); }
+ { $$ = makeIndexable($2,$1,$3); }
| a_expr LIKE a_expr
- { $$ = makeA_Expr(OP, "~~", $1, $3); }
+ { $$ = makeIndexable("~~", $1, $3); }
| a_expr NOT LIKE a_expr
{ $$ = makeA_Expr(OP, "!~~", $1, $4); }
| Op a_expr
return (Node *)a;
}
+static Node *makeIndexable(char *opname, Node *lexpr, Node *rexpr)
+{
+ Node *result = NULL;
+
+ /* we do this so indexes can be used */
+ if (strcmp(opname,"~") == 0)
+ {
+ if (nodeTag(rexpr) == T_A_Const &&
+ ((A_Const *)rexpr)->val.type == T_String &&
+ ((A_Const *)rexpr)->val.val.str[0] == '^')
+ {
+ A_Const *n = (A_Const *)rexpr;
+ char *match_least = palloc(strlen(n->val.val.str)+2);
+ char *match_most = palloc(strlen(n->val.val.str)+2);
+ int pos, match_pos=0;
+
+ /* skip leading ^ */
+ for (pos = 1; n->val.val.str[pos]; pos++)
+ {
+ if (n->val.val.str[pos] == '.' ||
+ n->val.val.str[pos] == '?' ||
+ n->val.val.str[pos] == '*' ||
+ n->val.val.str[pos] == '[' ||
+ n->val.val.str[pos] == '$')
+ break;
+ if (n->val.val.str[pos] == '\\')
+ pos++;
+ match_least[match_pos] = n->val.val.str[pos];
+ match_most[match_pos++] = n->val.val.str[pos];
+ }
+
+ if (match_pos != 0)
+ {
+ A_Const *least = makeNode(A_Const);
+ A_Const *most = makeNode(A_Const);
+
+ /* make strings to be used in index use */
+ match_least[match_pos] = '\0';
+ match_most[match_pos] = '\377';
+ match_most[match_pos+1] = '\0';
+ least->val.type = T_String;
+ least->val.val.str = match_least;
+ most->val.type = T_String;
+ most->val.val.str = match_most;
+ result = makeA_Expr(AND, NULL,
+ makeA_Expr(OP, "~", lexpr, rexpr),
+ makeA_Expr(AND, NULL,
+ makeA_Expr(OP, ">=", lexpr, (Node *)least),
+ makeA_Expr(OP, "<=", lexpr, (Node *)most)));
+ }
+ }
+ }
+ else if (strcmp(opname,"~*") == 0)
+ {
+ if (nodeTag(rexpr) == T_A_Const &&
+ ((A_Const *)rexpr)->val.type == T_String &&
+ ((A_Const *)rexpr)->val.val.str[0] == '^')
+ {
+ A_Const *n = (A_Const *)rexpr;
+ char *match_lower_least = palloc(strlen(n->val.val.str)+2);
+ char *match_lower_most = palloc(strlen(n->val.val.str)+2);
+ char *match_upper_least = palloc(strlen(n->val.val.str)+2);
+ char *match_upper_most = palloc(strlen(n->val.val.str)+2);
+ int pos, match_pos=0;
+
+ /* skip leading ^ */
+ for (pos = 1; n->val.val.str[pos]; pos++)
+ {
+ if (n->val.val.str[pos] == '.' ||
+ n->val.val.str[pos] == '?' ||
+ n->val.val.str[pos] == '*' ||
+ n->val.val.str[pos] == '[' ||
+ n->val.val.str[pos] == '$')
+ break;
+ if (n->val.val.str[pos] == '\\')
+ pos++;
+ /* If we have punctuation, this works well */
+ match_lower_least[match_pos] = tolower(n->val.val.str[pos]);
+ match_lower_most[match_pos] = tolower(n->val.val.str[pos]);
+ match_upper_least[match_pos] = toupper(n->val.val.str[pos]);
+ match_upper_most[match_pos++] = toupper(n->val.val.str[pos]);
+ }
+
+ if (match_pos != 0)
+ {
+ A_Const *lower_least = makeNode(A_Const);
+ A_Const *lower_most = makeNode(A_Const);
+ A_Const *upper_least = makeNode(A_Const);
+ A_Const *upper_most = makeNode(A_Const);
+
+ /* make strings to be used in index use */
+ match_lower_least[match_pos] = '\0';
+ match_lower_most[match_pos] = '\377';
+ match_lower_most[match_pos+1] = '\0';
+ match_upper_least[match_pos] = '\0';
+ match_upper_most[match_pos] = '\377';
+ match_upper_most[match_pos+1] = '\0';
+ lower_least->val.type = T_String;
+ lower_least->val.val.str = match_lower_least;
+ lower_most->val.type = T_String;
+ lower_most->val.val.str = match_lower_most;
+ upper_least->val.type = T_String;
+ upper_least->val.val.str = match_upper_least;
+ upper_most->val.type = T_String;
+ upper_most->val.val.str = match_upper_most;
+ result = makeA_Expr(AND, NULL,
+ makeA_Expr(OP, "~*", lexpr, rexpr),
+ makeA_Expr(OR, NULL,
+ makeA_Expr(AND, NULL,
+ makeA_Expr(OP, ">=", lexpr, (Node *)lower_least),
+ makeA_Expr(OP, "<=", lexpr, (Node *)lower_most)),
+ makeA_Expr(AND, NULL,
+ makeA_Expr(OP, ">=", lexpr, (Node *)upper_least),
+ makeA_Expr(OP, "<=", lexpr, (Node *)upper_most))));
+ }
+ }
+ }
+ else if (strcmp(opname,"~~") == 0)
+ {
+ if (nodeTag(rexpr) == T_A_Const &&
+ ((A_Const *)rexpr)->val.type == T_String)
+ {
+ A_Const *n = (A_Const *)rexpr;
+ char *match_least = palloc(strlen(n->val.val.str)+2);
+ char *match_most = palloc(strlen(n->val.val.str)+2);
+ int pos, match_pos=0;
+
+ for (pos = 0; n->val.val.str[pos]; pos++)
+ {
+ if ((n->val.val.str[pos] == '%' &&
+ n->val.val.str[pos+1] != '%') ||
+ (n->val.val.str[pos] == '_' &&
+ n->val.val.str[pos+1] != '_'))
+ break;
+ if (n->val.val.str[pos] == '%' ||
+ n->val.val.str[pos] == '_' ||
+ n->val.val.str[pos] == '\\')
+ pos++;
+ match_least[match_pos] = n->val.val.str[pos];
+ match_most[match_pos++] = n->val.val.str[pos];
+ }
+
+ if (match_pos != 0)
+ {
+ A_Const *least = makeNode(A_Const);
+ A_Const *most = makeNode(A_Const);
+
+ /* make strings to be used in index use */
+ match_least[match_pos] = '\0';
+ match_most[match_pos] = '\377';
+ match_most[match_pos+1] = '\0';
+ least->val.type = T_String;
+ least->val.val.str = match_least;
+ most->val.type = T_String;
+ most->val.val.str = match_most;
+ result = makeA_Expr(AND, NULL,
+ makeA_Expr(OP, "~~", lexpr, rexpr),
+ makeA_Expr(AND, NULL,
+ makeA_Expr(OP, ">=", lexpr, (Node *)least),
+ makeA_Expr(OP, "<=", lexpr, (Node *)most)));
+ }
+ }
+ }
+
+ if (result == NULL)
+ result = makeA_Expr(OP, opname, lexpr, rexpr);
+ return result;
+}
+
+
/* xlateSqlType()
* Convert alternate type names to internal Postgres types.
* Do not convert "float", since that is handled elsewhere
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