Yes it is possible. You need one ON for each join table. LEFT JOIN ab ON ab.sht = cd.sht LEFT JOIN aa ON aa.sht = cd.sht Incidentally my personal formatting preference for complex SQL is described in http://bentilly.blogspot.com/2011/02/sql-formatting-style.html. If you’re going to be writing a lot of this, it likely will help.
SELECT a.nid, GROUP_CONCAT(b.name ORDER BY b.id) DepartmentName FROM Notes a INNER JOIN Positions b ON FIND_IN_SET(b.id, a.forDepts) > 0 GROUP BY a.nid SQLFiddle Demo
SELECT p.pid, p.cid, p.pname, c1.name1, c2.name2 FROM product p LEFT JOIN customer1 c1 ON p.cid = c1.cid LEFT JOIN customer2 c2 ON p.cid = c2.cid
How about something like this: SELECT m.MESSAGEID, sum((case when mp.messageid is not null then 1 else 0 end)) FROM MESSAGE m LEFT JOIN MESSAGEPART mp ON mp.MESSAGEID = m.MESSAGEID GROUP BY m.MESSAGEID; The COUNT() function will count every row, even if it has null. Using SUM() and CASE, you can count only non-null values. EDIT: … Read more
You can try this User.find(:all, limit: 10, joins: “LEFT JOIN `user_points` ON user_points.user_id = users.id” , select: “users.*, count(user_points.id)”, group: “user_points.user_id”)
Try This SELECT f.* FROM first_table f LEFT JOIN second_table s ON f.key=s.key WHERE s.key is NULL For more please read this article : Joins in Sql Server
I thought that by not specifying a type of join it was assumed to be a LEFT JOIN. Is this not the case? No, the default join is an INNER JOIN. Here is a visual explanation of SQL joins. Inner join Left join
Another option might be array_remove(…, NULL) (introduced in 9.3) if tags.tag is NOT NULL (otherwise you might want to keep NULL values in the array, but in that case, you can’t distinguish between a single existing NULL tag and a NULL tag due to the LEFT JOIN): SELECT objects.*, array_remove(array_agg(tags.tag), NULL) AS tags, FROM objects … Read more
There is no difference between RIGHT JOIN and RIGHT OUTER JOIN. Both are the same. That means that LEFT JOIN and LEFT OUTER JOIN are the same. Visual Representation of SQL Joins
adapted from MSDN, how to left join using EF 4 var query = from u in usergroups join p in UsergroupPrices on u.UsergroupID equals p.UsergroupID into gj from x in gj.DefaultIfEmpty() select new { UsergroupID = u.UsergroupID, UsergroupName = u.UsergroupName, Price = (x == null ? String.Empty : x.Price) };