TOP 100+ SAP ABAP Interview Questions and Answers

1000+ SAP ABAP Interview Questions and Answers

1. Data Dictionary

What is the difference between a transparent table and a pooled table?

• Transparent Table: Directly corresponds to a database table and stores application data. It has a one-to-one relationship with a database table.
• Pooled Table: Multiple pooled tables are stored together in a single database table (table pool) to reduce database overhead.

What is the purpose of a type group in ABAP?

• A type group is a collection of reusable types (like constants, structures, and data types) defined in SE11. It allows developers to define commonly used data types in one place and use them across programs.

How do you create a foreign key relationship in SAP Data Dictionary?

1. Open the table in SE11.
2. Add a field that should reference another table.
3. Define the foreign key relationship in the Foreign Keys tab by specifying:
   • Check Table
   • Cardinality
   • Fields for relation

What is a search help, and how is it used?

• A Search Help provides F4 help for fields, allowing users to select values from a list.
• Used by associating it with table fields or screen fields via SE11.

Explain the difference between a table pool and a table cluster.

• Table Pool: Logical tables stored in a common physical table to reduce database load. Used for small, rarely accessed tables.
• Table Cluster: Groups logically related tables together for optimized access.

What are indexes in SAP ABAP, and how do they improve performance?

• Indexes are database objects that speed up data retrieval.
• Types: Primary Index (default) and Secondary Index (custom-defined for better search performance).

What is a domain and a data element?

• Domain: Defines value range and technical attributes (length, data type).
• Data Element: Provides semantic meaning to a field using a domain.

How do you enhance a standard table?

• Use Append Structure (Recommended) or Include Structure in SE11.

What is the difference between Append Structure and Include Structure?

• Append Structure: Adds fields to a standard table without modifying it.
• Include Structure: Allows reuse of structures in multiple tables.

What is a lock object, and how does it work?

• Prevents simultaneous updates to the same data by different users.
• Created in SE11 and used with ENQUEUE and DEQUEUE function modules.

SAP ABAP Interview Questions and Answers

2. Reports (Classical, Interactive, ALV)

What are the different types of reports in SAP ABAP?

1. Classical Reports (Basic output lists)
2. Interactive Reports (Allow user interaction with additional details)
3. ALV Reports (Enhanced, formatted reports using ALV Grid)

How do you create an interactive report in SAP ABAP?

• Use the event AT LINE-SELECTION to allow navigation to a detailed list when a user clicks a row.

What is an ALV report, and how does it differ from a classical report?

• ALV (ABAP List Viewer) reports provide better formatting, sorting, and filtering options compared to classical reports.

How do you use the REUSE_ALV_GRID_DISPLAY function module?

• Call REUSE_ALV_GRID_DISPLAY in your report and pass:
  • Field catalog (IT_FIELDCAT)
  • Output table (IT_OUTTAB)
  • Layout settings (IT_LAYOUT)

What is the purpose of the AT LINE-SELECTION event in reports?

• Allows users to select a row and display detailed data.

How do you optimize report performance?

• Use internal tables, indexing, buffering, and efficient SELECT queries.

What is the significance of event blocks in reports?

• Event blocks like INITIALIZATION, START-OF-SELECTION, END-OF-SELECTION control the report flow.

How do you handle user inputs in a report?

• Use PARAMETERS and SELECT-OPTIONS in selection screens.

How do you display totals and subtotals in an ALV report?

• Use IT_SORT table with DO_SUM = 'X'.

What is the use of a field catalog in ALV?

• Defines the properties of fields displayed in the ALV grid.

3. Select Query and Performance Optimization

What are the different types of SELECT statements in SAP ABAP?

• SELECT SINGLE, SELECT ENDSELECT, SELECT INTO TABLE, SELECT FOR ALL ENTRIES, INNER JOIN, LEFT JOIN.

What is the difference between SELECT SINGLE and SELECT UP TO 1 ROWS?

• SELECT SINGLE retrieves the first matching row (faster if primary key used).
• SELECT UP TO 1 ROWS fetches one row but may scan more data.

How can you improve the performance of a SELECT query?

• Use proper indexing, buffering, avoiding nested loops, and using FOR ALL ENTRIES.

What is buffering in SAP tables?

• Temporary storage of table data in memory to improve performance.

Explain the concept of aggregate functions in SAP ABAP.

• SUM, AVG, MIN, MAX, COUNT used to perform calculations in SELECT queries.

What is an inner join and an outer join?

• Inner Join: Returns matching records from both tables.
• Outer Join: Returns all records from one table and matching records from another.

How do you use FOR ALL ENTRIES in a select statement?

• Used to avoid multiple SELECT statements by fetching data in bulk.

What are database hints in SAP ABAP?

• Direct database optimizer to choose a specific access path.

How does indexing improve query performance?

• Speeds up data retrieval by providing a quick search mechanism.

How do you perform parallel processing in ABAP?

• Use asynchronous RFC (aRFC) or parallel processing using background jobs.

4. Module Pool Programming

What is module pool programming in SAP ABAP?

• It is dialog programming used to create custom screens (SE51) with user interactions.

How do you design a screen in module pool programming?

• Use Screen Painter (SE51) to create UI elements.

What is the difference between PAI and PBO events?

• PBO (Process Before Output): Prepares the screen before display.
• PAI (Process After Input): Handles user inputs.

How do you handle user input validations in module pool?

• Using PAI module and error messages.

What are table controls and how are they used in module pool?

• Interactive table UI elements for displaying and modifying data.

How do you use subscreens in module pool programming?

• Include them using CALL SUBSCREEN inside a main screen.

What is the purpose of a GUI status and GUI title?

• GUI Status: Defines menus, toolbar buttons.
• GUI Title: Displays the screen title.

How do you call a transaction from module pool?

• Using CALL TRANSACTION or LEAVE TO TRANSACTION.

What is a screen exit in SAP ABAP?

• A way to enhance standard screens without modifying SAP code.

How do you navigate between screens in module pool programming?

• Using CALL SCREEN, SET SCREEN, LEAVE TO SCREEN.

5. SAP Scripts and SmartForms

What is the difference between SAP Scripts and SmartForms?

• SAP Scripts: Older technology, client-dependent, requires layout, header, main, and footer windows.
• SmartForms: More advanced, easier to maintain, supports graphics and barcodes, client-independent.

How do you migrate a SAP Script to a SmartForm?

• Use the program RSTXSCRP to convert a SAP Script into a SmartForm.

What are the different components of a SAP Script?

• Layout Set, Standard Text, Print Program, and Output Device.

How do you call a SmartForm in an ABAP program?

• Use SSF_FUNCTION_MODULE_NAME to get the function module name and call it.

What is the function module used to call a SmartForm?

• Dynamically generated function module name from SSF_FUNCTION_MODULE_NAME.

What are the different types of windows in SAP Scripts?

• Main window, Secondary window, Constant window, Final window.

How do you debug a SAP Script?

• Use SE71 -> Utilities -> Activate Debugging or use SE80 with the print program.

How do you translate a SmartForm into different languages?

• Use transaction SE63 for translation.

What is a style in SAP Scripts?

• Defines fonts, paragraph formats, and styles for text formatting.

How do you print barcodes in SmartForms?

• Use barcode control in SmartStyle or SAPScript barcode printing techniques.

6. User Exits, Customer Exits, and BADI’s

What is the difference between a user exit and a customer exit?

• User Exit: Procedural enhancement using function modules.
• Customer Exit: Provided via SMOD and CMOD and supports both function modules and menu exits.

How do you implement a customer exit in SAP ABAP?

• Find the exit via SMOD, activate it via CMOD, and implement custom logic inside the function module.

What is a BADI, and how is it different from a user exit?

• BADI (Business Add-In) is object-oriented and supports multiple implementations, whereas user exits allow only one implementation.

How do you find user exits available in a transaction?

• Use transaction SE93 or search in SE84.

What are the different types of BADIs in SAP?

• Classical BADIs and New BADIs (enhancement framework).

How do you implement multiple implementations of a BADI?

• Create multiple implementations via SE19.

What is an enhancement spot in SAP ABAP?

• A predefined point where custom code can be inserted.

What is the difference between an explicit and an implicit enhancement?

• Explicit Enhancement: Defined by SAP at specific points.
• Implicit Enhancement: Available at end of reports, function modules, or methods.

How do you use BAdI filter values?

• Define a filter type in SE18 and use it in SE19 implementations.

How do you de-implement a customer exit?

• Deactivate the exit in CMOD.

7. BDC (Batch Data Communication) and BAPIs

What is the difference between BDC and BAPI?

• BDC is used for screen-based data input (transaction recording), while BAPI is a standardized API for business processes.

How do you create a BDC session?

• Use CALL TRANSACTION or SESSION METHOD with BDC_INSERT.

What are the different modes in BDC?

• A (Display all screens)
• E (Display errors only)
• N (No screens, background processing)

How do you handle errors in BDC processing?

• Store error messages in an internal table and log errors in SM35.

What is the difference between CALL TRANSACTION and SESSION method?

• CALL TRANSACTION: Immediate execution, faster.
• SESSION METHOD: Runs in background via SM35.

What are the advantages of using BAPIs over BDCs?

• More stable, supports object-oriented programming, does not rely on screen changes.

How do you find a suitable BAPI for a transaction?

• Use BAPI Explorer (SE37) or SE84.

What is the difference between synchronous and asynchronous BAPIs?

• Synchronous: Immediate execution and response.
• Asynchronous: Runs in background without waiting for completion.

How do you create a custom BAPI?

1. Create a function module.
2. Set it as a Remote-enabled Function Module (RFC).
3. Define in the BAPI transaction.

What is the purpose of the BAPI_TRANSACTION_COMMIT function module?

• Ensures that database updates are committed after calling a BAPI.

8. Object-Oriented Programming in ABAP (OOPS ABAP)

What are the basic concepts of OOPS ABAP?

• Encapsulation, Inheritance, Polymorphism, Abstraction.

What is a class and an object in SAP ABAP?

• Class: Blueprint that defines behavior and attributes.
• Object: Instance of a class.

What is the difference between instance and static methods?

• Instance Method: Works with instance-specific data.
• Static Method: Works without an instance.

What is inheritance in OOPS ABAP?

• Allows a class to inherit properties of another class.

How do you implement polymorphism in ABAP?

• Method Overriding and Interfaces.

What are interfaces in ABAP OOPS?

• A contract that defines methods without implementation.

What is an abstract class?

• A class that cannot be instantiated and only serves as a base.

What is the purpose of the constructor method?

• Initializes object properties when an object is created.

How do you implement events in OOPS ABAP?

• Use RAISE EVENT and EVENT HANDLER.

What is the difference between a local and a global class?

• Local Class: Defined in a single program.
• Global Class: Created in SE24 and reusable across programs.

9. SPAU and SPDD

What is the purpose of SPAU in SAP?

• Used during upgrades to adjust repository objects modified by SAP.

What is SPDD, and when is it used?

• SPDD is used for dictionary objects (tables, structures) during an upgrade.

What is the difference between SPAU and SPDD?

• SPAU: Adjusts programs, function modules.
• SPDD: Adjusts dictionary objects.

How do you reset modifications in SPAU?

• Reset to SAP standard via SPAU transactions.

What happens if you don’t adjust changes in SPDD during an upgrade?

• Custom table fields may be lost.

How do you identify modified objects in SPAU?

• Run transaction SPAU and filter modified objects.

What are the risks of not adjusting SPAU and SPDD?

• Loss of custom changes after an upgrade.

What is a note correction in SPAU?

• SAP-provided fix for issues in modified objects.

How do you merge custom and SAP standard changes in SPDD?

• Manually adjust table fields to retain custom changes.

What are the best practices for handling SPAU adjustments?

• Backup custom changes before upgrade, review each modification carefully.

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