*

*

* IDENTIFICATION

* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.92 1998/01/1704:53:16 momjian Exp $

* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.93 1998/01/1705:01:34 momjian Exp $

*

* HISTORY

* AUTHORDATEMAJOR EVENT

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);

n->subselect = $7;

$$ = (Node *)n;

}

/* We accept all Operators? */

| '(' row_descriptor ')' Op '(' SubSelect ')'

{

SubLink *n = makeNode(SubLink);

n->subselect = $6;

$$ = (Node *)n;

}

/* Do we need this?

| '(' row_descriptor ')' Op '(' row_descriptor ')'

{

SubLink *n = makeNode(SubLink);

n->lefthand = $2;

n->subLinkType = OPER_SUBLINK;

n->oper = lcons($4, NIL);

n->subselect = $6;

$$ = (Node *)n;

$$ = makeRowExpr($4, $2, $6);

}

*/

;

row_descriptor: row_list ',' a_expr

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(ERROR,"Unequal number of entries in row expression");

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(ERROR,"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;

}

void

mapTargetColumns(List *src, List *dst)

{