简体   繁体   English

SQL Server:如果列值为空,则插入

[英]SQL Server: Insert if column values are null

I am newbie to SQL queries so sorry for this basic question. 我是SQL查询的新手,所以很抱歉这个基本问题。

I want to insert values into a table where column's value is null 我想将值插入表中列值为null的表中

I tried following 我尝试了以下

INSERT INTO SystemUsers(FilePath)
If @FilePath IS Null
values('C:\Users\Developer\Desktop\MvcApplication8\MvcApplication8\App_Data\Uploads\Lighthouse.jpg')

and

INSERT INTO SystemUsers(FilePath)
where FilePath IS Null
values('C:\Users\Developer\Desktop\MvcApplication8\MvcApplication8\App_Data\Uploads\Lighthouse.jpg')

But that didn't work, how can I insert default values in a column whether column's values are null? 但这不起作用,无论列的值是否为空,如何在列中插入默认值?

Maybe what you want is the UPDATE command and not the insert something like this 也许您想要的是UPDATE命令,而不是像这样插入

UPDATE SystemUsers
SET FilePath = 'C:\Users\Developer\Desktop\MvcApplication8\MvcApplication8\App_Data\Uploads\Lighthouse.jpg'
WHERE FilePath is null
UPDATE SystemUsers
    SET FilePath = 'C:\Users\Developer\Desktop\MvcApplication8\MvcApplication8\App_Data\Uploads\Lighthouse.jpg'
WHERE FilePath is null

Where clause normaly comes after the operation you are doing. where子句通常在您执行操作之后出现。

声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM