JPA - FindByExample

Question

Does anyone have a good example for how to do a findByExample in JPA that will work within a generic DAO via reflection for any entity type? I know I can do it via my prov

Answer 1

https://github.com/superbiger/sbiger-jpa-qbe

I'think query by example with single table like mybatis is easy to use

base on jpa we can also support Join/GroupBy like this:

/*
SQL:
    select * from
        user 
    where
        id=1 
        or id=2 
    group by  
        id,  
        name   
    order by  
        id asc,
        name asc 
    limit ?
*/
public List findAll(){
    Example example = ExampleBuilder.create();
    example.or()
            .andEqual("id", 1)
            .orEqual("id", 2);
    example.groupBy("id","name");
    example.asc("id","name");
    return userReponsitory.findAll(example, new PageRequest(0, 1));
}

Features now:

• Support and/or logic operation
• Support is(Empty/Boolean/Null)
• Support Equal/NotEqual/In/NotIn/Like/NotLike
• Support gt/ge/lt/le/between
• Support join query
• Support group by
• Support custom specification.
• Support pagination
  more features coming soon……