Set Operators

I am going to promote my series of very short articles or tidbits on Transaction SQL Operators. An operator is a symbol specifying an action that is performed on one or more expressions. I will exploring the Set Operators today. A Venn diagram is used to express different operations between sets. The above image represents the four possible operations given two sets, A and B, and three operators. We will get into the operators supported by Microsoft Transaction SQL shortly. To demonstrate these operators, we need a two temporary tables…

Selecting Data – Part 2

The SELECT reserved word is part of the Data Manipulation Language (DML) defined by Codd and is used to query data from the database. Because of its popularity, there are many clauses and functions that can be used to construct a query to retrieve data. Today, I am continuing our exploration of this reserved word by reviewing queries that merge data using joins and unions. Six known join types exist in SQL Server. The definitions are based upon joining TABLE A (left) with TABLE B (right). Inner Join – Include…