Question

我想在现有表中添加一列，为两个查询返回“不匹配”：

select * from dbo.customer  
where cus_title IN ('MRS','DAME','SISTER','MISS','MADAME','LADY','MS')  
and cus_gender <> 'F'

select * from pv_customer 
where  cus_title IN ('FATHER','SIR','MR') 
and cus_gender <> 'M'

或'匹配'，如果未从上述两个查询中选择？

是否有人能够协助进行alter table查询？

非常感谢

Answer 1

您只需添加列并运行如下更新语句：

ALTER TABLE <table_name>
ADD COLUMN match_status VARCHAR(10) NULL;

UPDATE <table_name> SET match_status = 'match';

假设您正在更新的这个表有一个客户ID的外键，那么您将使用以下内容更新非匹配：

UPDATE <table_name> SET match_status = 'non-match' 
WHERE customerId IN (select customerId from dbo.customer where cus_title IN ('MRS','DAME','SISTER','MISS','MADAME','LADY','MS') and cus_gender <> 'F')
OR customerId IN (select customerId from pv_customer where cus_title IN ('FATHER','SIR','MR') and cus_gender <> 'M');

Answer 2

这听起来像计算列的工作！与运行UPDATE不同，计算列的优点是，如果添加新行或更新现有行，则会自动更新。

创建一个这样的函数：

CREATE FUNCTION [dbo].[fn_GenderMatch](@title VARCHAR(50), @gender CHAR(1)) RETURNS VARCHAR(10)
WITH SCHEMABINDING AS
BEGIN
    IF (((@title IN ('MRS', 'MS', 'MISS')) AND (@gender = 'M'))
        OR
        ((@title IN ('MR', 'SIR', 'FATHER')) AND (@gender = 'F')))
    BEGIN
        RETURN 'non-match'
    END
    RETURN 'match'
END
GO

如果要在此列上编制索引，WITH SCHEMABINDING很重要！虽然，如果要索引，我建议更改函数以返回BIT。哎呀，使用BIT对于存储来说也更好，而且对于其他比较也更清洁。

然后像这样改变你的桌子：

ALTER TABLE [dbo].[customer] ADD [MisMatch] AS [dbo].[fn_GenderMatch]([cus_title],[cus_gender])

Answer 3

ALTER TABLE [SomeTable] ADD COLUMN Check VARCHAR(10)

UPDATE [SomeTable]
SET Check = 'No Match'

UPDATE S
SET Check = 'Match'
FROM 
[SomeTable] S JOIN dbo.Customers C ON s.CustomerID = C.CustomerId
AND C.cus_title IN
('MRS','DAME','SISTER','MISS','MADAME','LADY','MS')  and C.cus_gender <>
 'F'
JOIN Pv_Customer P ON S.CustomerID = P.CustomerID AND 
P.cus_title IN ('FATHER','SIR','MR')
and P.cus_gender <> 'M'

SQL查询 - 如果两个现有列匹配，则添加新列

3 个答案: