I have this method:
public List<User> getReport(String name, int age, String sName, Date bd,
String address, String msg2, int first, int pageSize) {
List<User> result = new ArrayList<>();
result = em.createQuery("from User u, User.class)
.setFirstResult(first)
.setMaxResults(pageSize)
.getResultList();
return result;
}
Now, this method return all data. I need sett dynamicly parameters. I can make this:
result = em.createQuery("from User u WHERE u.age = :age", User.class)
.setParameter("age", age)
.setFirstResult(first)
.setMaxResults(pageSize)
.getResultList();
But if my age
is null - I dont get result. And with another fields.
I need somethign like:
if(age != null){
em.createQuery("from User u WHERE u.age = :age", User.class)
.setParameter("age", age)
}
if(name!= null){
em.createQuery("from User u WHERE u.age = :age AND u.name= :name", User.class)
.setParameter("age", age)
}
I can format string query like:
String query = "from User u WHER";
and them concate this string
if(age != null){
query = query +"u.age = :age";
em.createQuery("from User u WHERE u.age = :age", User.class)
.setParameter("age", age)
}
But I thing it is bad practice.
All parameters are picking up the map, as I create a dynamic query.
You can try:
public List<User> getReport(String name, Integer age, String sName, Date bd,
String address, String msg2, int first, int pageSize) {
Map<String, Object> paramaterMap = new HashMap<String, Object>();
List<String> whereClause = new ArrayList<String>();
StringBuilder queryBuilder = new StringBuilder();
queryBuilder.append("select u from User u ");
if (!name.isEmpty()){
whereClause.add(" u.name =:name ");
paramaterMap.put("category", category);
}
if (age != null){
whereClause.add(" u.age =:age ");
paramaterMap.put("age", age);
}
if (!sName.isEmpty()){
whereClause.add(" u.sName =:sName ");
paramaterMap.put("sName", sName);
}
if (bd != null){
whereClause.add(" u.bd =:bd ");
paramaterMap.put("bd", bd);
}
if (!address.isEmpty()){
whereClause.add(" u.address =:address ");
paramaterMap.put("address", address);
}
if (!msg2.isEmpty()){
whereClause.add(" u.msg2 =:msg2 ");
paramaterMap.put("msg2", msg2);
}
queryBuilder.append(" where " + StringUtils.join(whereClause, " and "));
Query jpaQuery = entityManager.createQuery(queryBuilder.toString());
for(String key :paramaterMap.keySet()) {
jpaQuery.setParameter(key, paramaterMap.get(key));
}
jpaQuery.setFirstResult(first)
jpaQuery.setMaxResults(pageSize)
return jpaQuery.getResultList();
}