QueryDSL: convert list of BooleanExpression to Predicate
11,538
To construct complex boolean expressions, use the com.querydsl.core.BooleanBuilder
class. It implements Predicate
and can be used in cascaded form. For example:
public List<Customer> getCustomer(String... names) {
QCustomer customer = QCustomer.customer;
JPAQuery<Customer> query = queryFactory.selectFrom(customer);
BooleanBuilder builder = new BooleanBuilder();
for (String name : names) {
builder.or(customer.name.eq(name));
}
query.where(builder);
return query.fetch();
}
BooleanBuilder
is mutable and initially represents null. After each and
or or
call it represents the result of the operation.
Author by
Paweł Kozikowski
Updated on June 09, 2022Comments
-
Paweł Kozikowski almost 2 years
I'm trying to create a query that would depend on number of boolean parameters. The function that creates the predicate looks like this:
Predicate createPredicate(Boolean param1, Boolean param2) { List<BooleanExpression> booleanExpressions = new List<>(); if (param1) booleanExpressions.add(/** expression 1 **/); if (param2) booleanExpressions.add(/** expression 2 **/); convertExpressionsToPredicate(booleanExpressions); }
The problem is the
convertExpressionsToPredicate
function. Is there any special method in querydsl to join list of expressions into one predicate using theor
operator?The solution I'm looking for should convert this:
List<BooleanExpression> booleanExpressions = List(exp1, exp2, exp3);
into:
Predicate p = exp1.or(exp2).or(exp3)