DECLARE var_name [, var_name] ... type [DEFAULT value]

This statement is used to declare local variables within stored programs. To provide a default value for the variable, include a DEFAULT clause. The value can be specified as an expression; it need not be a constant. If the DEFAULT clause is missing, the initial value is NULL.

Local variables are treated like stored routine parameters with respect to data type and overflow checking. See Section 12.1.12, “CREATE PROCEDURE and CREATE FUNCTION Syntax”.

Local variable names are not case sensitive.

The scope of a local variable is within the BEGIN ... END block where it is declared. The variable can be referred to in blocks nested within the declaring block, except those blocks that declare a variable with the same name.