Variables used in the body of a procedure, trigger, or batch can be declared using the DECLARE statement. The variable persists
for the duration of the compound statement in which it is declared. If you specify initial-value, the variable is set to that value. If you do not specify an initial-value, the variable contains the NULL value until a different value is assigned by the SET statement.
The body of a Watcom SQL procedure or trigger is a compound statement, and variables must be declared with other declarations,
such as a cursor declaration (DECLARE CURSOR), immediately following the BEGIN keyword. In a Transact-SQL procedure or trigger,
there is no such restriction.
If you specify initial-value, the data type must match the type defined by data-type.