SQL Syntax Reference : DECLARE
 
DECLARE
Remarks
Use the DECLARE statement to define a SQL variable.
This statement is allowed only inside of a stored procedure, a user-defined function, or a trigger.
The name of a variable must begin with a colon (:), both in the definition and use of the variable or parameter. A variable must be declared before it can be set to a value with SET.
Use a separate DECLARE statement for each variable (you cannot declare multiple variables with a single statement). Specify a value or values for data types that require a size, precision, or scale, such as CHAR, DECIMAL, NUMERIC, and VARCHAR.
Examples
The following examples show how to declare variables, including ones that require a value for size, precision, or scale.
DECLARE :SaleItem CHAR(15);
DECLARE :CruiseLine CHAR(25) DEFAULT 'Open Seas Tours'
DECLARE :UnitWeight DECIMAL(10,3);
DECLARE :Titration NUMERIC(12,3);
DECLARE :ReasonForReturn VARCHAR(200);
DECLARE :Counter INTEGER = 0;
DECLARE :CurrentCapacity INTEGER = 9;
DECLARE :Cust_ID UNIQUEIDENTIFIER = NEWID()
DECLARE :ISO_ID UNIQUEIDENTIFIER = '1129619D-772C-AAAB-B221-00FF00FF0099'
See Also
CREATE FUNCTION
CREATE PROCEDURE
CREATE TRIGGER
SET