In this post, you’ll learn about the error message -312 undefined or unusable host variable variable-name in the IBM DB2 database , the reason why it occurs along with the solution to fix it
IBM DB2 Error Message
-312 undefined or unusable host variable variable-name
Reason for the Error
The host variable ‘variable-name’ appears in the SQL statement, but either no declaration for a variable of that name appears in the application program, or the attributes are improper for the specified usage.
Solution
Verify that the variable name is spelled properly in the SQL statement, that the variable is allowed in the SQL statement, that the application program contains a declaration for that variable, and that the attributes of the variable are compatible with its use in the statement.