Question

我正在使用SQL Server2008。我有2个表Table1和Table2。

Table1具有列

SchoolCode, District, Type, SchoolName

和Table2的列

SchoolCode1, District1, Type1, SchoolName1

两个表中的

SchoolCode列具有相同的代码，例如“ 1234”； schoolcode列中的代码都相同。

现在，如果两个表中的District都为Type，则我想将SchoolName的{{1}}，Table1和Table2列值从SchoolCode复制到filling_values=0一样。

我认为查询将使用联接，但是我不知道它是如何工作的。对我如何执行此任务有帮助吗？

Answer 1

如果在复制时表示要更新行，则可以在连接中使用update语句

update t2
set 
    District1= District, 
    Type1= Type, 
    SchoolName1= SchoolName
from Table1 t1
join
Table2 t2
on t1.SchoolCode=t2.SchoolCode1

Answer 2

我可以给你一点点想法。在这里：

Insert into table2 (District1, Type1, SchoolName1)
SELECT District, Type, SchoolName
FROM table1
where table1.Schoolcode=table2.Schoolcode1

Answer 3

您必须使用内部联接将表1中的数据更新到表2，内部联接将联接相等的值。。要了解有关联接的更多信息，强烈建议您阅读以下文章

SQLServer Joins Explained - W3Schools

为方便起见，请使用下面的代码。.

DECLARE @Table1 TABLE
(
    SchoolCode  INT, 
    District    VARCHAR(MAX), 
    Type        VARCHAR(MAX), 
    SchoolName  VARCHAR(MAX)
)

DECLARE @Table2 TABLE
(
    SchoolCode1  INT, 
    District1   VARCHAR(MAX), 
    Type1       VARCHAR(MAX), 
    SchoolName1 VARCHAR(MAX)
)




INSERT INTO @Table1
        ( SchoolCode ,District , Type , SchoolName
        )
VALUES  ( 1 ,'DIS1' ,'X' ,'A'),
        ( 2 ,'DIS2' ,'Y' ,'B'),
        ( 3 ,'DIS3' ,'Z' ,'C'),
        ( 4 ,'DIS4' ,'D' ,'D'),
        ( 5 ,'DIS5' ,'K' ,'E')



INSERT INTO @Table2
        ( SchoolCode1 ,District1 , Type1 , SchoolName1
        )
VALUES  ( 1 ,'DIS1' ,'X' ,'A'),
        ( 2 ,NULL ,'Z' ,NULL),
        ( 3 ,'DIS3' ,'Z' ,'C'),
        ( 4 ,NULL ,'Z' ,'S'),
        ( 5 ,'DIS5' ,'K' ,'E')
--BEFORE

SELECT * FROM @Table1
SELECT * FROM @Table2

--Logic UPDATE Table 2
UPDATE t2 SET   t2.District1 = t1.District,
                t2.Type1 = t1.Type,
                t2.SchoolName1 = t1.SchoolName
FROM @Table1 t1
INNER JOIN @Table2 t2 ON t1.SchoolCode = t2.SchoolCode1
-- End Logic UPDATE Table 2

--AFTER
SELECT * FROM @Table1
SELECT * FROM @Table2

Answer 4

您可以在UPDATE语句中联接表。

请注意，我已将table1和table2这两个表分别命名为t1和t2。

这就是我所做的：

create table Table1
(SchoolCode varchar(50),
District  varchar(50),[Type]  varchar(50),SchoolName  varchar(50))
go
create table Table2
(SchoolCode1 varchar(50), District1  varchar(50),[Type1]  varchar(50),SchoolName1  varchar(50))
go
insert into table1 values ('1234','District1','High','Cool School')
insert into table1 values ('2222','District2','Lower','Leafy School')
insert into table2 (SchoolCode1) values ('1234')
go
update t2
set District1 = District,
    Type1 = [Type],
    SchoolName1 = SchoolName
from table1 t1 
join table2 t2
on t2.SchoolCode1 = t1.SchoolCode
go
select * from table2
go

匹配代码并复制列

4 个答案: