Question

我有一个查询返回某些记录的旧版本（由于数据库设计不好），我尝试只获取最新版本。所以我尝试使用Max Id＆s进行查询，但查询很复杂且有很多记录。所以像这样的子选择查询不会起作用：

SELECT row 
FROM table 
WHERE id=(
    SELECT max(id) FROM table
    )

这是我的疑问。顺便说一下，我的公司正在使用Testlink，如果你熟悉它并且你有更好的解决方案，我们将不胜感激。

SELECT req_doc_id, scope,nh.parent_id,nh.id
FROM (SELECT nh.id, req_doc_id,doc_id FROM nodes_hierarchy nh,
req_specs r1, requirements r2 
WHERE nh.parent_id = r1.id AND nh.id = r2.id 
AND (r1.doc_id LIKE '%BlaBla%' OR r1.doc_id LIKE '%Tralala%')) 
AS t1, nodes_hierarchy nh, req_versions r1 
WHERE t1.id = nh.parent_id AND nh.id = r1.id

结果集是

 NAME..................ID              
____

BlaBla1..............163        

BlaBla1..............190

BlaBla2..............173

Tralala..............15

Tralala2.............26

Tralala2.............19

我想要的是：

 NAME..................ID              
____


BlaBla1..............190

BlaBla2..............173

Tralala..............15

Tralala2.............26

Answer 1

SELECT TB.NAME,TB.ID FROM TABLE TB
INNER JOIN
(
   SELECT NAME,MAX(ID) ID FROM TABLE GROUP BY NAME
)INNERTABLE ON INNERTABLE.ID=TB.ID

尝试以上查询。

Answer 2

你走了：

 SELECT Name,Notes
 FROM (select nh.id ,req_doc_id as Name, scope as Notes  from 
 (select nh.id,req_doc_id,doc_id  from nodes_hierarchy nh ,
 req_specs r1, requirements r2 
 where nh.parent_id = r1.id  and nh.id = r2.id 
 and ( r1.doc_id like '%Tralala%'
 or r1.doc_id like '%BlaBla' ) )    

 as t1,
 nodes_hierarchy nh, req_versions r1 
 where t1.id = nh.parent_id  and nh.id = r1.id ) AS TABLO
 INNER JOIN(
 SELECT MAX(nh.id) ID ,scope FROM  (select nh.id,req_doc_id,doc_id  from nodes_hierarchy nh ,
 req_specs r1, requirements r2 
 where nh.parent_id = r1.id  and nh.id = r2.id 
 and (r1.doc_id like '%Tralala%'
 or r1.doc_id like '%BlaBla' ) )  

 as t1, nodes_hierarchy nh, req_versions r1 where t1.id = nh.parent_id  and nh.id = r1.id GROUP BY req_doc_id)
 INNERTABLE on INNERTABLE.ID = TABLO.ID;

SQL如果记录重复，请选择最大ID为

2 个答案: