Hi suresh,
1.The Field Checks
As already mentioned Transaction is the only method, which SAP recommends to update the database tables. Data entered in the database table should be valid and correct. Data entered is validated at each and every point. ABAP/4 offers various methods to validate data and those are as follows:
• Automatic field checks
• Checks performed in the flow logic
• Checks performed in the ABAP/4 module pool program
in the user-defined transaction by using AT EXIT-COMMAND. This module can Automatic Field Checks
These checks are based on the field information stored in the dictionary. These checks are performed by the system automatically when the user enters the data for the screen field. System performs these checks before PAI event is triggered. Types of field checks performed by system are as follows:
• Required input
While designing the screen, for particular screen field if you click the Req. Entry checkbox, the field becomes mandatory. When the transaction is executed if user leaves this particular field blank, the system displays error message. User cannot proceed until the user enters some data.
• Proper Data Format
Each field has its own data format whether it is table field or screen field. Whenever data is entered, system checks for the proper format of the data. For example date. Each user has its own format for date, which is defined in the user master record. If the date defined in the user master record is in the format DD/MM/YYYY, if the user enters the date, say, in YY/DD/MM, the user displays the error message. System also checks for the value of month or days. For example if month entered is greater than twelve then the error message is displayed.
• Valid Value for the Field
In data dictionary two tables are related by Primary key-Foreign key relationship. Whenever the user enters the data, the system checks for the check table values. Also in Domain, if you have fixed values, then the system checks for these values.
Automatic field checks are repeated each time the user enters the data.
About at Exit – Command
Automatic field checks can be avoided by AT EXIT-COMMAND, which works exactly the same way as Cancel works on application tools bar. In the R/3 screen, if you want to quit the processing of that particular screen without entering the mandatory fields, user can click the Cancel button. Same functionality can be incorporated be called before the system executes the automatic field checks and it goes without saying that before PAI event. Code for AT EXIT-COMMAND in flow logic and in module pool program can be written as follows:
In Flow Logic
Process After Input.
Module exit AT EXIT-COMMAND.
In module pool program.
Module exit.
Case okcode.
When ‘Exit’.
Leave to screen 0.
To achieve this kind of functionality a pushbutton or menu item should be assigned a function type ‘E’. It tells the system to process this particular module before carrying out any field checks.
for the remaining answers u can check the above answers...
Bluesky
