I have query which filters items by certain conditions:
@NamedQueries({
@NamedQuery(
name = ITEM.FIND_ALL_PARAMS_BY_COMPANY_COUNTRY_GROUP,
query = "SELECT i FROM Item i where "
+ "((i.idCompany=:companyId AND i.idEMGroup=:groupId) "
+ "OR (i.idCompany=:companyId AND i.idEMCountry =:countryId AND i.idEMGroup is null) "
+ "OR (i.idCompany is null AND i.idEMCountry = :countryId AND i.idEMGroup is null)) "
+ "order by i.idEMCountry desc, i.idCompany desc, i.idEMGroup desc")
})
In some cases parameters idEMGroup o companyId can be null which generates sql looking like this IdEmCompany = 200630758) AND (IdEMGroup = NULL)
and it is incorrect sql syntax is it possible to dynamically if value is null for it as 'Column IS NULL'
instead of 'Column = NULL'
without adding a lot of if's, or it's just better to rewrite this query using Criteria API and just check if value is present and add predicates on certain conditions ?
Correct answer would be to use CriteriaQuery
.
Though it is also possible to construct the query dynamically but manipulating @NamedQuery
is not possible or might require stuff that makes it not worth to do.
Instead you could construct the query first as a String
and create TypedQuery
by manipulating the query string
String strQuery = "SELECT i FROM Item i"; // .. + the rest of stuff
if(null==companyId) {
// add something like "companyId IS :companyId"
// ":companyId" coulöd also be NULL"
// but to enable using tq.setParameter("companyId", companyId)
// without checking if there is param "companyId" so there always will
} else {
// add something like "companyId=:companyId"
}
TypedQuery<Item> tq = entityManager.createQuery(strQuery, Item.class);
tq.setParameter("companyId", companyId);
There will be some IF
s but so will be in CriteriaQuery
construction also.