MySQL动态条件查询，可用于JPA自定义SQL多条件查询

今天分享一个mysql的小技巧。在使用JPA操作数据库的时候，常常要自定义SQL，但是有很多条件是不确定的，所以要通过动态判断。现在太晚了，我先把代码贴出来，JPA带分页查询，供大家参考，等以后有时间了，我在来详细说明。

@Query( value =  "SELECT * FROM result a, sheet b, user c, users d, type e\n" +
        " WHERE a.task_sheet_id = b.id AND b.test_type_id = e.id AND b.test_user_id = c.id AND c.user_id = d.id  " +
        " AND if(:code = '' OR :code is null ,1=1, b.code like %:code%) " +
        " AND if(:name = '' OR :name is null ,1=1, d.`name` like %:name%) " +
        " AND if(:status = '' OR :status is null ,1=1, b.start_status = :status) ",
        countQuery = "SELECT count(*) \n"+
        "FROM test_result a, task_sheet b, user_test c, admin_users d, test_type e\n" +
        "WHERE a.task_sheet_id = b.id AND b.test_type_id = e.id AND b.test_user_id = c.id AND c.user_id = d.id "+
        " AND if(:code = '' OR :code is null ,1=1, b.code like %:code%) " +
        " AND if(:name = '' OR :name is null ,1=1, d.`name` like %:name%) " +
        " AND if(:status = '' OR :status is null ,1=1, b.start_status = :status) ",
        nativeQuery = true)
Page<Map> findTestResultGetTaskAll(Object code,Object name,Object status,Pageable pageable);