public SqlRexConvertlet get(SqlCall call) {
SqlRexConvertlet convertlet;
final SqlOperator op = call.getOperator();
// Is there a convertlet for this operator
// (e.g. SqlStdOperatorTable.plusOperator)?
convertlet = (SqlRexConvertlet) map.get(op);
if (convertlet != null) {
return convertlet;
}
// Is there a convertlet for this class of operator
// (e.g. SqlBinaryOperator)?
Class<? extends Object> clazz = op.getClass();
while (clazz != null) {
convertlet = (SqlRexConvertlet) map.get(clazz);
if (convertlet != null) {
return convertlet;
}
clazz = clazz.getSuperclass();
}
// Is there a convertlet for this class of expression
// (e.g. SqlCall)?
clazz = call.getClass();
while (clazz != null) {
convertlet = (SqlRexConvertlet) map.get(clazz);
if (convertlet != null) {
return convertlet;
}
clazz = clazz.getSuperclass();
}
return null;
}
public void validateCall(
SqlCall call,
SqlValidator validator,
SqlValidatorScope scope,
SqlValidatorScope operandScope) {
// This implementation looks for the quantifier keywords DISTINCT or
// ALL as the first operand in the list. If found then the literal is
// not called to validate itself. Further the function is checked to
// make sure that a quantifier is valid for that particular function.
//
// If the first operand does not appear to be a quantifier then the
// parent ValidateCall is invoked to do normal function validation.
super.validateCall(call, validator, scope, operandScope);
validateQuantifier(validator, call);
}