Then performs the WHERE, ORDER BY, GROUP BY, HAVING clauses with the SEELCT statement last. So if in statement #1 above, the table is smaller, the SQL engine has less work …

T-SQL (SQL Server) follows this strictly and you can't use SELECT aliases until you've passed SELECT. But in MySQL it's possible to use SELECT aliases in the HAVING clause even …

I am having performance issues on certain database queries that have large possible result sets. The query in question, I have three ANDs in the WHERE clause Does the order of the clauses …

To the question "What are sql clauses?" most of the resources on internet simply provide a list of clauses and explain what they do. But I'm trying to understand in abstract terms how it is …

Given a table users with two fields: id and email. select id, email as electronic_mail from ( select id, email from users ) t where electronic_mail = '' Postgres complains that:

@HLGEM The View actually contains multiple queries to multiple databases on different servers, and it joins them all by a UNION ALL. It's much easier to use a View than to have to rewrite …

Despite the foregoing, this is almost inevitable given the myriad ways SQL allows us to specify the same logical query specification. Even so, it would be a mistake to infer anything you see from …

Is there a way to execute multiple operations using the WITH statement? Something like WITH T AS ( SELECT * FROM Tbl ) BEGIN OPEN P_OUTCURSOR FOR SELECT * FROM T; …

I want to create VIEW using WITH clauses, but really can't find any references on correct syntax. I want smth like this WITH TempTbl AS (SELECT ...) CREATE VIEW SomeView SELECT * …

If CONDITION 3 is FALSE, will CONDITION 4 be checked? What about conditions on WHERE: does the SQL Server engine optimize all conditions in a WHERE clause? Should …