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Software ==>	SQL (203 exercises)
Topic ==>	Dynamic SQL (4 exercises)
Level ==>	Relatively easy
Subject ==>	SQL training

Create a stored procedure which can change the name of the table in the FROM clause

This exercise is provided to allow potential course delegates to choose the correct Wise Owl Microsoft training course, and may not be reproduced in whole or in part in any format without the prior written consent of Wise Owl.

Before you can do this exercise, you'll need to download and unzip this file . Once you've done this:

Go into SQL Server Management Studio;
Open the SQL file you've just unzipped (you can press CTRL + O to do this); then
Execute this script.

This will generate the database that you'll need to use in order to do this exercise (note that the database and script are only to be used for exercises published on this website, and may not be reused or distributed in any form without the prior written permission of Wise Owl).

The aim of this exercise is to be able to pass different table names to a select statement, to show different sets of rows. First create a stored procedure which selects everything from the table tblEvent:

The first few events.

Now add a varchar(max) parameter called @TableName to hold the name of the table from which you want to extract data, and use its value in place of tblEvent in the FROM clause. Sadly this doesn't work and results in an error:

It takes a while to accept that this can't work!

Declare a varchar(max) variable called @SQL, and set it equal to the SQL script up to the FROM keyword, then add your parameter value on the end:

DECLARE @SQL VARCHAR(MAX) =

'SELECT * FROM ' +

@TableName

Then finally either use EXEC (@SQL) or Exec SP_SQLEXEC @SQL at the bottom of the stored procedure to run the select statement contained in your variable.

Now try running the stored procedure: