Tag: T-SQL

There are many times where returning all the data held within all the columns in a table are unnecessary and inefficient.

For example.

SELECT * FROM HumanResources.Department

If you expand out the HumanResources.Department then you will get a list of the columns as well as some information on the columns.

To get only the DepartmentID and Name columns the following query would be needed.

SELECT DepartmentID,Name FROM HumanResources.Department

There is a simple way to return information from all the columns in SQL.

SELECT * FROM INSERTTABLENAME

For example

SELECT * FROM HumanResources.Department

As you can see the query returned 16 rows of information with all the columns.

Before you can start querying a database you will need to select the database first.

This is done using the USE command

USE Enteryourdatabasenamehere

For example

USE AdventureWorks

This will change the queried database to AdventureWorks

In a time-honoured tradition in every programming language the first thing they teach you is how to get the system to put ‘Hello World’ on to your screen.

This is accomplished by using the below command.

PRINT ‘HELLO WORLD’

Play about with the PRINT command and see what else you can get the system to reproduce.

The SELECT query is the basis of SQL and is the most commonly used syntax within SQL.

SELECT basically means retrieve.

For example the query SELECT 1 returns 1.

SELECT ‘This is an example of the SELECT statement’

As you can see the SELECT query is simply retrieving the number or word and returning that as a result.

If you want information from a database within a table then you must select a database and table.