SQL Server, the ANSI_WARNINGS option

Hi Guys,
Welcome back!

Have you five minutes to learn about the ANSI_WARNINGS option? Yes i suppose!

 

Introduction

Some days ago we talked about the option XACT_ABORT.
Seeing the great success today I will show you another option, the ANSI_WARNINGS!

Who knows exactly what ANSI_WARNINGS is for?
Well only five minutes of reading and you will know all about this option!

ANSI_WARNINGS option

The ANSI_WARNINGS option controls behavior of the SQL Server database engine for various error conditions.

When the ANSI_WARNINGS option is set to ON, the engine follows the standard ISO behavior for this situations:

  • Encountering a NULL value during an aggregation operation
  • Encountering a Divide by Zero error
  • String truncation

Example for the string truncation

Let's take a table name Table_A where the field CODICE is a varchar datatype with a length of 4 character:

If i execute the insert below where in the field codice i insert a value that have a length greater than 4 char i get an error:



Now we set the ANSI_WARNINGS to OFF and execute the same insert again.
What do we get?

This time the insert was succesful but the values for the codice field was truncated.

In the the same way if ANSI_WARNINGS is OFF and also then SET ARITHABORT option is set to OFF no error will be returned dividing a number by 0

P.S. How to determine is the ANSI_WARNINGS is set to ON?

Try This: 

       
DECLARE @options INT
SELECT @options = @@OPTIONS
IF ( (8 & @options) = 8 ) PRINT 'ANSI_WARNINGS'

That's all for today.
See you soon,
Luca



 
Luca Biondi @ SQLServerPerformance blog 2020!













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