An SQL variable you define inside a stored procedure is a procedure-owned variable. Its scope is that procedure in which it is declared; you can only refer to it within that procedure. If a procedure calls another procedure, the procedure-owned variable of the calling procedure cannot be directly used in the called procedure; instead, it must be passed in a parameter. You cannot declare a procedure-owned variable more than once in the same stored procedure.

If a compound statement is the body of a stored procedure, then no SQL variable name declared in that procedure can be identical to a parameter name in the parameter list of that procedure. For more information about compound statements, refer to Compound Statement.

For more information about the syntax of this statement, refer to the following topic in SQL Engine Reference: SET.