Sql查询可以添加更多约束 [英] Sql query can we add more constraints

问题描述

如果一个表有这些列::



列ID ::列名:::列desc :::列a ::列b



如果查询是从表中选择*，其中columnid像'0';



其返回数据与columnid 0 only



我们可以这样做:: select * from table其中columnid如'0'，'1'，'2'; ？

if a table have these columns ::

Column ID:: Column Name ::: Column desc ::: column a :: Column b

and if the query is select * from table where columnid like '0';

its return data related to columnid 0 only

and can we do this :: select * from table where columnid like '0','1','2'; ?

推荐答案

ColumnID IN ('0','1','2') 

如果你只是寻找bitid值为0的记录，那么这是更好的：

Hi,

If you're only looking for the record that has the columnid value of 0, then this is better:

select * from table where columnid = '0';

你真的不能这样做：

You can't really do:

select * from table where columnid like '0','1','2';

如果您要检索columnid值为0 1的记录或2，然后这将工作：

If you are trying to retrieve records that have a columnid value of 0 1 or 2, then this would work:

select * from table where columnid IN ('0','1','2');

...如果将columnid定义为整数数据类型，那么你最好用：

... and if columnid is defined as an integer data type, then you would be better with:

select * from table where columnid IN (0,1,2);

希望有所帮助。

Hope it helps.

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