Development Guidelines

1.1. General

• Only one statement per line
• Use a template for creation of ABAP programs with the standard includes
• Indent the program for readability

• Creation of variables

1. Parameter – P_
2. Select option – S_
3. Radio button – RB_
4. Ranges – R_
5. Checkbox – PX_
6. Constants – C_
7. Counters – N_
8. Internal tables – IT_
9. Sorted – IS_
10. Hashed – IH_
11. Structure – X_
12. Flags – FG_
13. Global variables – G_
14. Local variables – L_
15. All literals that are displayed on a report must use Text Elements
16. Use GUI_UPLOAD and GUI_DOWNLOAD to upload or download data

1.2. Guidelines for Internal tables

• Read internal table WITH KEY particularly for sorted and hashed
• Read only the needed fields thru TRANSPORTING
• Use the BINARY search wherever possible
• Avoid nested looping
• Avoid COLLECT statement
• Specify the sort fields
• Use COMPARING for deleting duplicate data in the internal tables
• Do not use index operations while populating sorted tables
• Do not resort a sorted type of an internal table
• Index operations cannot be used on hashed tables
• Do not use OCCURS 0 in the declaration unless less than 8K data is stored.
• Use CLEAR to initialize the header record
• Use REFRESH to clear the contents of the internal table. This statement does not clear the header record
• Use FREE to free the resources used by the internal table

1.3. Optimization

• Remove all code and variables that are not used in the program
• Perform the Extended Program Check
• Use selection criteria to effectively select and limit the number of database reads
• Select only those columns that are needed – Do not use a SELECT * unless necessary
• Use aggregate functions wherever required
• To update table entries, specify the columns
• Use a SELECT SINGLE if the primary keys are known, otherwise SELECT UPTO 1 ROWS
• Do not use nested SELECTs – Use views, joins or the FOR ALL ENTRIES option
• Do not use SELECTs in loops
• Restrict the database access by using the WHERE clause – do not use a CHECK
• Use indexes wherever available
• Avoid NOT in the WHERE condition
• Do not select the same data more than once
• To populate an internal table thru a SELECT, use the INTO addition
• Use sort on the internal table for small amounts of data and database ORDER BY for larger amount