Now, TMG Events are hooks (user-exits) provided by SAP within the Table Maintenance Generator. They let you insert custom logic during specific points of table maintenance processing — without modifying SAP standard code.

Uses of TMG Events

• To perform validations before saving data.
• To default values when creating new entries.
• To restrict or control user actions (e.g., prevent deletion of certain entries).
• To update dependent tables automatically when the main table is changed.
• To call function modules, BAPIs, or custom programs at certain points in the table maintenance cycle.

How TMG Events Work

When you create a TMG for a table (via SE11 → Utilities → Table Maintenance Generator), SAP provides a list of predefined events (like “before saving the data”, “after saving”, “before deleting”, etc.).

Each event corresponds to a FORM routine in an include program (L<tablename>F01), where you can write your custom ABAP code.

Examples of TMG Events

Some commonly used events:

• 01 – Before saving the data in the database
  → Use to validate entries or prevent saving if conditions aren’t met.
• 02 – After saving the data in the database
  → Useful to update dependent/custom tables.
• 05 – Creating a new entry
  → Can default field values.
• 21 – Before deleting an entry
  → Prevent deletion of critical data (e.g., master records in use).

Example Scenario:

Suppose you have a ZCUSTOMER_CONFIG table maintained via TMG.

• If the user enters an invalid plant code, you can use Event 01 (Before saving) to check the plant in T001W. If invalid → show error and prevent saving.
• If a new record is created, use Event 05 to default the “Created By” and “Created On” fields automatically.

Events in TMG are used to:

• Validate data before it’s saved.
• Set default values when creating entries.
• Restrict access to rows based on user roles.
• Log changes or trigger custom logic.
• Enforce complex business rules beyond field-level checks.

Where You Configure TMG Events

1. Transaction: SE54 (Table/View Maintenance)
2. Choose: Environment → Events
3. Select your table/view and function group
4. Choose the desired event number and implement the ABAP logic

TMG Events

• Maintain data in custom or standard tables without writing ABAP code.
• Provide a standardized UI for table maintenance.
• Enforce data consistency and validation through events and screen logic.

How to Create a TMG

1. Go to SE11 → Create or open your Z-table.

2. Ensure:

   • Delivery class = C, L, or G (client-dependent or -independent).

   • Table is not pooled or clustered.

   • Table has a primary key.

3. Click on Utilities → Table Maintenance Generator.

4. Enter:

   • Authorization group (e.g., &NC& for none).

   • Function group (create one if needed).

   • Maintenance type: One-step or two-step.

5. Click Create → Save & Activate.

Now, you can maintain the table via transaction SM30.

One-Step vs Two-Step