com.sap.cds.jdbc.postgresql.PostgreSqlPredicateMapper Maven / Gradle / Ivy
/************************************************************************
* © 2020-2023 SAP SE or an SAP affiliate company. All rights reserved. *
************************************************************************/
package com.sap.cds.jdbc.postgresql;
import com.sap.cds.impl.parser.builder.ExpressionBuilder;
import com.sap.cds.impl.parser.token.CqnPlainImpl;
import com.sap.cds.jdbc.spi.PredicateMapper;
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.CqnPlain;
import com.sap.cds.ql.cqn.CqnPredicate;
import com.sap.cds.ql.cqn.Modifier;
import com.sap.cds.ql.impl.ExpressionVisitor;
import com.sap.cds.ql.impl.LeanModifier;
public class PostgreSqlPredicateMapper implements PredicateMapper {
private static final CqnPlain IS_NOT_DISTINCT_FROM = CqnPlainImpl.plain("is not distinct from");
private static final CqnPlain IS_DISTINCT_FROM = CqnPlainImpl.plain("is distinct from");
@Override
public CqnPredicate apply(CqnPredicate pred) {
Modifier m = new LeanModifier() {
@Override
public Predicate comparison(Value lhs, Operator op, Value rhs) {
if (!rhs.isNullValue()) {
if (op == Operator.IS) {
return ExpressionBuilder.create(lhs, IS_NOT_DISTINCT_FROM, rhs).predicate();
}
if (op == Operator.IS_NOT) {
return ExpressionBuilder.create(lhs, IS_DISTINCT_FROM, rhs).predicate();
}
}
return LeanModifier.super.comparison(lhs, op, rhs);
}
};
return ExpressionVisitor.copy(pred, m);
}
}