Deleting rows in database

I am using visual studio 2008 with my database in sql server 2005. I have created a chat online app. Once the user is online he/she can chat and his/her chat data will go in my message database which has this schema.

1. MessageID(pk)
2. RoomID
3. UserID
4. ToUserID
5. Text

After the chatter finishes chat he log's开发者_如何学Python out and the messages sent by the "UserID" or say chat data in message table of that USerID must be deleted.

So I want to delete multiple rows from the database at once.

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Well, this is my first response in SO, so I hope I get it right.

The usual way to delete more rows in SQL languages is:

delete from (table_name) where userID = (ID_of_the_user_that_signed_off)

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Something like the following should help:

DELETE FROM [YOUR TABLENAME] WHERE UserId = [UserID]

Note: You can have a where clause in your delete statement using which you can specify the delete criteria.

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If you want to delete the entire chat sessions in all rooms and with all users. Use the following query.

DELETE FROM [TABLENAME] WHERE UserId = @UserID

If you want to delete the chat with specific room then you have to specify room id also

Use the following query.

DELETE FROM [TABLENAME] WHERE UserId = @UserID AND RoomID = @RoomID

If you want to delete the chat with specific user session then you have to specify chat person user id also

Use the following query.

DELETE FROM [TABLENAME] WHERE UserId = @UserID AND ToUserID = @ToUserID