Sql server® 2012 t-sql fundamentals

 

CHAPTER 10

 

Programmable Objects

 

 343

Batches and Variables

A variable is local to the batch in which it is defined. If you try to refer to a variable that was defined 

in another batch, you will get an error saying that the variable was not defined. For example, the fol-

lowing code declares a variable and prints its content in one batch, and then tries to print its content 

from another batch.

DECLARE @i AS INT; 

SET @i = 10; 

-- Succeeds 

PRINT @i; 

GO 

 

-- Fails 

PRINT @i;

The reference to the variable in the first PRINT statement is valid because it appears in the same 

batch where the variable was declared, but the second reference is invalid. Therefore, the first PRINT 

statement returns the variable’s value (10), whereas the second fails. Here’s the output returned from 

this code.

10 

Msg 137, Level 15, State 2, Line 3 

Must declare the scalar variable "@i".