Logical Operators

I am going to make headway on the 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 Logical Operators today. In short, these operators return either a boolean TRUE or FALSE. To demonstrate many of these operators, we need a temporary table to query against. The Transaction SQL code below creates a table that contains the first eight prime numbers. Any complex real world programming example probably has…

Selecting Data – Part 4

Today, I am continuing our exploration of the SELECT reserved word by talking about sub-queries. A sub-query is a query that is nested inside a SELECT, INSERT, UPDATE, or DELETE statement, or inside another sub-query. Sub-queries can be used anywhere an expression is allowed or can be nested inside another sub-query. I will be using the AdventureWorks Sample database supplied by Microsoft during this talk.

One usage a sub-query is with comparison operators in the where clause. The example below returns all the sales people by name and id…

Selecting Data – Part 1

The SELECT reservered word is part of the Data Manipulation Language (DML) defined by Codd and is used to query data from the database as recordsets. Because of its popularity, there are many clauses and functions that can be used to construct a query to retrieve data. All reserved words that I introduce below will be in CAPS below. Today, I would like to review simple SELECT queries using the AdventureWorks Sample database supplied by Microsoft. The most basic use of the SELECT statement is to return a constant as…