where子句中的条件 [英] conditions in where clause

问题描述

我希望以下查询根据@date和@abc传递返回记录。如果我没有为param @abc传递任何值，那么查询应该只考虑日期结果并根据该返回记录。做什么更改要做在下面的查询中？

目前我有以下查询..

select * from table where date = @ date and abc = @ abc

I want the following query to return records according to @date and @abc passed.If i did not pass any value for param @abc then query should just consider the date conndition and return records according to that.what changes to do in following query?
at present i have the following query..
select * from table where date=@date and abc=@abc

推荐答案

尝试：

Try:

SELECT * FROM table WHERE date=@date AND (@abc IS NULL OR abc=@abc)

你应该检查这样一个条件你的代码并执行一个不同的查询，即

You should check such a a condition in your code and execute a different query, namely

select * from table where date=@date

用于忽略'empty' abc 参数。

您可以使用if ... else ...条件来检查它是否有数据。

You can use if...else... condition to check whether it is having data or not.

if @date and @abc is not null
begin
    "Your select statement" Where date=@date and abc=@abc
end
if @date is not null and @abc is null
begin
    "Your select statement" Where date=@date 
end
if @date is null and @abc is not null
begin
    "Your select statement" Where abc=@abc
end

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