How to Perform a Left Join in Sql Server Between Two Select Statements?
I Have Two Select Statements in Sql Server Like These: (Select [Userid] from [User]) (Select [Tailuser], [Weight] from [Edge] Where [Headuser] = 5043) I Want...
I have two SELECT statements in SQL Server like these:
(SELECT [UserID] FROM [User])
(SELECT [TailUser], [Weight] FROM [Edge] WHERE [HeadUser] = 5043)
I want to perform a LEFT JOIN between these two SELECT statements on [UserID] attribute and [TailUser] attribute. I want to join existent records in second query with the corresponding records in first query and NULL value for absent records. How can I do this?
4 Answers
SELECT * FROM
(SELECT [UserID] FROM [User]) a
LEFT JOIN (SELECT [TailUser], [Weight] FROM [Edge] WHERE [HeadUser] = 5043) b
ON a.UserId = b.TailUser
SELECT [UserID] FROM [User] u LEFT JOIN (
SELECT [TailUser], [Weight] FROM [Edge] WHERE [HeadUser] = 5043) t on t.TailUser=u.USerID
select *
from user
left join edge
on user.userid = edge.tailuser
and edge.headuser = 5043
Try this:
SELECT user.userID, edge.TailUser, edge.Weight
FROM user
LEFT JOIN edge ON edge.HeadUser = User.UserID
WHERE edge.HeadUser=5043
OR
AND edge.HeadUser=5043
instead of a WHERE clause.
Sarah Jenkins is a veteran tech journalist with over 12 years of experience covering artificial intelligence, mobile innovations, and digital ethics. Her insights have appeared in leading technology publications worldwide.
