Checking Input values

REPORT Test.
PARAMETERS: p_carrid like spfli-carrid OBLIGATORY.

Consider the above program. Suppose we need to check the validity of parameter p_carrid, then usually we write a SELECT statement to verify the entries. If the SELECT statement fails, then we issue an error message. Instead of following the above procedure, there is a simple method i.e., the addition of VALUE CHECK to the PARAMETERS.

REPORT Test.
PARAMETERS: p_carrid like spfli-carrid OBLIGATORY VALUE CHECK.

Here the datatype must refer to the data type from the dictionary. If a check table or a list of fixed values is defined in the ABAP Dictionary for the relevant type, the user can only enter these valid values. Otherwise, the system issues an error message in the status bar of the selection screen when the selection screen is processed. Since this check is performed even if the input field is empty, you should use the VALUE CHECK addition only for required fields.

In the example above, parameter p_carrid is declared with reference to field CARRID of database table SPFLI. For this field, check table SCARR is specified in the ABAP Dictionary. The user can only enter carrier ID values that are contained in SCARR.