19.2.7.1. DECLARE Local Variables
DECLARE var_name[,...] type [DEFAULT value]
This statement is used to declare local variables. 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 routine parameters with
respect to data type and overflow checking. See
Section 19.2.1, “CREATE PROCEDURE and CREATE FUNCTION Syntax”.
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.
