MSSQL update multiple rows based on select statement

I am trying to update multiple rows in one table, based on a select statement on another table.

This is my query:

UPDATE dbo.[user_message_content]
SET [status] = 1
WHERE [message_id] = (SELECT [message_id] FROM dbo.[user_message] WHERE [receiver_id] = @userID)
AND [status] = 0

This select statement may return multiple rows, which leads me to this error:

Msg 512, Level 16, State 1, Procedure usp_profileUserMessageMarkAsRead, Line 11 Subquery returned more than 1 value. This is not permitted when the subq开发者_JS百科uery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

What is the correct way to achieve what I need?

Thanks very much

If you want to update all those records, change the = to IN:

UPDATE dbo.[user_message_content]
SET [status] = 1
WHERE [message_id] IN 
    ( SELECT [message_id] FROM dbo.[user_message] WHERE [receiver_id] = @userID )
AND [status] = 0

You can also use UPDATE with FROM clause http://msdn.microsoft.com/en-us/library/aa260662(SQL.80).aspx.

USE tempdb; 
    GO

    create table #user_message_content([status] int, message_id int)
    create table #user_message (message_id int,receiver_id int)

    declare @UserID int

    UPDATE mc
    SET mc.[status] = 1
    FROM #user_message_content mc join #user_message m on mc.message_id = m.message_id 
    WHERE m.receiver_id = @userID
          AND mc.[status]=0;

    drop table #user_message_content
    drop table #user_message

I think you need to use a join to do this

USE dbo; // Sets the current database to dbo, I did this for readability

UPDATE user_message_content join user_message on user_message_content.message_id = user_message.message_id 
SET user_message_content.status = 1
WHERE user_message.receiver_id = @userID;