How to select Distinct records from SQL without a primary key
- by Satheesh
I need to show a Notification on user login if there is any unread messages.So if multiple users send(5 messages each) while the user is in offline these messages should be shown on login.Means have to show the last messages from each user.
I use joining to find records.
In this scenario Message from User is not a primary key.
This is my query
SELECT UserMessageConversations.MessageFrom, UserMessageConversations.MessageFromUserName,UserMessages.MessageTo, UserMessageConversations.IsGroupChat, UserMessageConversations.IsLocationChat,
UserMessageConversations.Message, UserMessages.UserGroupID,UserMessages.LocationID FROM UserMessageConversations LEFT OUTER JOIN
UserMessages ON UserMessageConversations.UserMessageID = UserMessages.UserMessageID ![enter image description here][1]Where UserMessageConversations.MessageTo=743 AND UserMessageConversations.ReadFlag=0
This is the output obtained from above query.
MessageFrom -582 appears twice. I need only one record of this User.
How is it possible