Variables, Parameters, and Return Codes

Variables

Variables provide a way to manipulate, store, and pass data within a stored procedure as well as between stored procedures and functions. SQL Server has two types of variables: local and global. A local variable is designated by a single @ symbol whereas a global variable is designated by a double @@ symbol. Additionally, you can create, read, and write local variables whereas you can’t create or write to global variables. Table 12-1 lists some of the more common global variables.

Table 12-1. Global Variables

Global Variable

Definition

@@ERROR

Error code from the last statement executed

@@IDENTITY

Value of the last identity value inserted within the connection

@@ROWCOUNT

The number of rows affected by the ...

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