For this problem, as for many others involving non-trivial left joins such as left-joining on inner-joined tables, I find it convenient and somewhat more readable to split the query with a with …

The SQL JOIN clause allows you to associate rows that belong to different tables. For instance, a CROSS JOIN will create a Cartesian Product containing all possible combinations of rows …

Nov 1, 2013 · Instead of one join with OR it turned into three joins. With each condition in a seprate join and a final join to get that one matching row from either first or second join.

May 9, 2013 · Is it possible to write join query without ON statement? and how do these joins differ LEFT JOIN, RIGHT JOIN works.

If the join is a LEFT/RIGHT/FULL OUTER JOIN, then it is not a matter of preference or performance, but one of correct results. The SQL Cookbook (§ 11.3. Incorporating OR Logic …

Of course, all other categories will be populated with null in the user_category_subscriptions columns. Conversely, a where clause does the join, and then reduces the rowset. So, this …

Jan 6, 2012 · When using LEFT JOIN or RIGHT JOIN, it makes a difference whether you put the filter in the WHERE or into the JOIN. See this answer to a similar question I wrote some time …

Feb 27, 2017 · If name is indexed and 'e' is somewhat unique then do that first is more efficient. This is different SELECT * FROM tableA LEFT JOIN tableB ON tableB.id = tableA.id WHERE …

Nov 10, 2014 · Here is my code SELECT ID, Name, Phone FROM Table1 LEFT JOIN Table2 ON Table1.ID = Table2.ID WHERE Table1.ID = 12 AND Table2.IsDefault = 1 The problem …

Mar 23, 2010 · When I use the following LEFT OUTER JOIN, I get a table with all the types of rail, with nulls in the rows where nothing happened on the 19th. Now, this is only working because …