您好我对sql server
有疑问部门
+---------+--------+
| deptkey | deptno |
+---------+--------+
| 1 | 100 |
| 2 | 101 |
| 3 | -1 |
+---------+--------+
LOC
+--------+-------+
| lockey | locid |
+--------+-------+
| 1 | 200 |
| 2 | 201 |
| 3 | -1 |
+--------+-------+
反
+----+--------+-------+------+
| id | deptno | locid | Name |
+----+--------+-------+------+
| 1 | 100 | 201 | abc |
| 2 | 101 | 203 | def |
| 3 | 103 | 200 | rav |
| 4 | 105 | 204 | jai |
| 1 | 101 | 200 | kal |
| 4 | 100 | 206 | lo |
+----+--------+-------+------+
这里tran deptno = dept.deptno然后相应的键值带来如果不匹配那么我们需要unmatched deptno assign -1和相应的键需要反向 类似的tran locid = loc.locid
基于上面的表我想要输出如下
+----+------+---------+--------+
| id | Name | deptkey | lockey |
+----+------+---------+--------+
| 1 | abc | 1 | 2 |
| 2 | def | 2 | 3 |
| 3 | rav | 3 | 1 |
| 4 | jai | 3 | 3 |
| 1 | kal | 2 | 1 |
| 4 | lo | 1 | 3 |
+----+------+---------+--------+
我尝试过以下查询
SELECT a.[id],a.name ,b.deptkey,c.lockey
FROM [trans] a left join dept b on a.deptno=b.deptno
left join loc c on a.locid=c.locid
上面的查询没有给出预期的结果你能告诉我如何在sql server中编写查询来实现这个任务
答案 0 :(得分:0)
SELECT a.[id],a.name ,b.deptkey,c.lockey
FROM [trans] a left join dept b on isnull(a.deptno,-1)=isnull(b.deptno,-1)
left join loc c on a.locid=c.locid
试试这个...
答案 1 :(得分:0)
SELECT
a.[id]
, a.name
, ISNULL(b.deptkey,-1) AS [deptkey]
, ISNULL(b.lockey,-1) AS [lockey]
FROM [trans] a
left join dept b
on a.deptno = b.deptno
left join loc c
on a.locid = c.locid
如果找不到值ISNULL
,请将结果更改为-1
而不是NULL
。您只需将-1
与您偏好的任何default value
更改为无法匹配。
如果您需要查询驱动的默认值(将最后一条记录作为默认值),则为OR。您可以更改脚本,如下所示。
SELECT
a.[id]
, a.name
, ISNULL(b.deptkey,(SELECT TOP 1 deptno from dept ORDER BY deptkey DESC)) AS [deptkey]
, ISNULL(b.lockey,(SELECT TOP 1 locid from loc ORDER BY lockey DESC)) AS [lockey]
FROM [trans] a
left join dept b
on a.deptno = b.deptno
left join loc c
on a.locid = c.locid
答案 2 :(得分:0)
SELECT a.[id],a.name ,
(CASE WHEN b.deptkey IS NULL THEN (select deptkey from DEPT WHERE DeptNo = -1)
ELSE b.deptkey END) AS 'deptkey',
(CASE WHEN c.lockey IS NULL THEN (select LocKey from LOC WHERE LocId = -1)
ELSE c.lockey END) AS 'lockey '
FROM [trans] a left join dept b on a.deptno=b.deptno
left join loc c on a.locid=c.locid