com.sap.cds.jdbc.generic.GenericPredicateModifier Maven / Gradle / Ivy
/************************************************************************
* © 2020-2023 SAP SE or an SAP affiliate company. All rights reserved. *
************************************************************************/
package com.sap.cds.jdbc.generic;
import static com.sap.cds.impl.builder.model.ComparisonPredicate.eq;
import static com.sap.cds.impl.builder.model.ComparisonPredicate.ne;
import static com.sap.cds.ql.CQL.and;
import static com.sap.cds.ql.CQL.or;
import com.sap.cds.ql.Predicate;
import com.sap.cds.ql.Value;
import com.sap.cds.ql.cqn.CqnComparisonPredicate.Operator;
import com.sap.cds.ql.cqn.CqnPredicate;
import com.sap.cds.ql.impl.LeanModifier;
public class GenericPredicateModifier implements LeanModifier {
@Override
public Predicate comparison(Value lhs, Operator op, Value rhs) {
switch (op) {
case IS:
// (a = b AND a IS NOT NULL AND b IS NOT NULL) OR (a IS NULL AND b IS NULL)
CqnPredicate bothNotNull = and(lhs.isNotNull(), rhs.isNotNull());
CqnPredicate bothNull = and(lhs.isNull(), rhs.isNull());
return or(and(eq(lhs, rhs), bothNotNull), bothNull);
case IS_NOT:
// ((a <> b OR a IS NULL OR b IS NULL) AND (a IS NOT NULL OR b IS NOT NULL))
CqnPredicate eitherNull = or(lhs.isNull(), rhs.isNull());
CqnPredicate eitherNotNull = or(lhs.isNotNull(), rhs.isNotNull());
return and(or(ne(lhs, rhs), eitherNull), eitherNotNull);
default:
return LeanModifier.super.comparison(lhs, op, rhs);
}
}
}