Error
Error Code:
406
SAP S/4HANA Error 406: SQL Generated Column Update
Description
This error occurs during an INSERT operation when an attempt is made to explicitly provide a value for a column that is automatically generated by the database. It signifies a mismatch between the data being inserted and the database schema's handling of generated values, preventing the operation from completing.
Error Message
ERR_SQL_CANT_UPDATE_GEN_COL
Known Causes
3 known causesExplicit Value for Generated Column
An INSERT statement includes a value for a column that the database automatically generates, which is not permitted.
Incorrect Schema Definition
The database table's schema defines a column as generated, but the application attempts to treat it as a standard insertable column.
Application Data Mapping Error
The application's data mapping or ORM configuration incorrectly attempts to populate a generated column during an insert operation.
Solutions
3 solutions available1. Identify and Remove Direct Updates to Generated Columns medium
Locate and modify ABAP code or SQL statements that attempt to directly update generated columns.
1
Analyze ABAP programs or SQL statements that interact with the table containing the generated column. The error message `ERR_SQL_CANT_UPDATE_GEN_COL` indicates that the system is trying to perform a direct `UPDATE` or `INSERT` operation on a column defined as 'generated' in the database schema.
2
Review the table definition in the SAP Data Dictionary (Transaction SE11) to confirm which columns are marked as 'Generated'. Generated columns are typically derived from other columns and their values are automatically computed by the database.
3
Modify the ABAP code or SQL statements to remove any explicit assignments to the generated column. The value of a generated column should be managed by the database's generation logic, not by direct user input or program logic.
Example of problematic ABAP code (pseudo-code):
DATA: lv_generated_value TYPE some_type.
" ... logic to calculate lv_generated_value ...
UPDATE your_table SET generated_column = lv_generated_value WHERE ... .
Correct approach: Remove the UPDATE statement for generated_column. The database will handle its value.4
If the generated column's value is intended to influence other columns, ensure that the underlying columns used in the generation logic are being updated correctly. The database will then re-calculate the generated column automatically.
2. Leverage Database-Level Generation Logic for Data Integrity medium
Ensure that data is inserted or updated in a way that respects the database's generated column definitions.
1
Understand the definition of the generated column. Generated columns can be of two types: 'stored' (values are physically stored) or 'virtual' (values are computed on the fly when queried). The error occurs when you try to overwrite the database's calculation.
2
When inserting new rows, only provide values for the non-generated columns. The database will automatically compute and populate the generated column.
Example SQL INSERT statement:
INSERT INTO your_table (column1, column2, ...) VALUES (value1, value2, ...);3
When updating existing rows, update the columns that the generated column depends on. The database will then automatically re-calculate the generated column's value.
Example SQL UPDATE statement:
UPDATE your_table SET column_influencing_generated = new_value WHERE ... ;
(Do NOT include the generated_column in the SET clause.)4
If you are using an ORM or any abstraction layer, ensure it is configured to respect the database's generated column definitions and does not attempt to set values for these columns.
3. Re-evaluate Data Model and Application Logic advanced
Thoroughly review the data model and application logic to ensure generated columns are used as intended.
1
Consult the SAP S/4HANA functional and technical documentation for the specific module or area where this error is occurring. Understand the purpose and behavior of the generated column in the context of the application.
2
Perform a comprehensive review of all data manipulation logic (ABAP, SQL, interfaces) that interacts with the table. Identify any custom developments or modifications that might be contributing to the issue.
3
If the generated column is part of a standard SAP S/4HANA table, consider if a configuration setting or a standard enhancement might be causing the conflict. SAP Notes and Support Packages should be checked.
4
If the generated column was created as part of a custom extension or a specific business requirement, re-evaluate the design. It's possible the initial design did not account for the implications of generated columns, and a redesign might be necessary to correctly derive or manage the data.