如何使用sqlsubqueries获取特定id的数据（我正在使用sql子查询IN）

Question

大家好我正在使用sql子查询IN进行两次sql查询.am获取所有id的数据但我需要获取perticualar id的数据我怎么能写下面是我的查询

SELECT g.title 
FROM`object_reference` b, object_data a,`object_reference` d,
      `tree` e,`object_reference` f,`object_data` g,`tree` c 
WHERE a.`obj_id` = b.`obj_id` 
  AND b.`ref_id` = c.`parent` 
  AND c.`child` = d.`ref_id` 
  AND d.`ref_id` = e.`parent` 
  AND e.`child` = f.`ref_id` 
  AND f.`obj_id` = g.`obj_id` 
  AND a.type='tst' IN(
      SELECT c.child 
      FROM object_data a,`object_reference` b,`tree` c 
      WHERE a.`obj_id` = b.`obj_id`
        AND b.`ref_id` = c.`parent` 
        AND a.obj_id=3217)

以下是一些示例数据：

table object_data:

obj_id | type | title 
-------+------+------
3217   |crs   |it 
3221   |grp   |xyz 
3228   |tst   |test 
3264   |tst   |test3 

table object_reference:

ref_id | obj_id 
-------+---------
337    |3217       
338    |3221      
343    |3228 
371    |3264

table tree:

tree | child | parent 
-----+-------+------
1    |338    |337 
2    |343    |338 
3    |371    |337

以下是样本数据的预期结果：

obj_id|title
------+-----
 3228 |test
 3264 |test3

Answer 1

尝试此查询：

SELECT A.obj_id, A.title
FROM object_data A JOIN object_reference B
ON A.obj_id=B.obj_id 
JOIN (SELECT C.child FROM tree C 
WHERE NOT EXISTS (SELECT null 
             FROM. tree D
             WHERE D.parent=C.child)) E
ON B.ref_id=E.child;