Question

我有两个表，它们有两个公共列'StationID'。

Create table t1(ID int, StationID bigint)
insert into t1 values
(0,1111),
(1,2222),
(2,34),
(3,456209),
(56,78979879),
(512,546)
go
Create table t2(StationID bigint, Descr varchar(50))
insert into t2 values
(-1,'test-1'),
(0,'test0'),
(1,'test1'),
(2,'test2'),
(5001,'dummy'),
(5002,'dummy'),
(6001,'dummy')
go

现在我们注意到并非每个t1.StationID都在t2.StationID中。运行脚本可以证明它。

select distinct StationID from t1 as A
where not exists
(select * from t2 as B where B.StationID =A.StationID)

结果是：

StationID
34
546
1111
2222
456209
78979879

现在我想用上面丢失的StationID填充t2，列Descr可以是任何虚拟数据。我的真实案例有数千条记录，如何使用脚本来实现它？

Answer 1

insert into t2 (StationID, Descr)
select distinct StationID, 'dummy' 
from t1 as A
where not exists
   (select * from t2 as B where B.StationID =A.StationID)

Answer 2

INSERT INTO 
    t2 
SELECT DISTINCT 
    stationid, 'dummy'  
FROM 
    t1 
WHERE 
    stationid NOT IN (SELECT stationid FROM t2)

（作为其他人的替代方案）。

将丢失的数据插入表中

2 个答案: