How To Fix DA661 - Non-supported type change for table &1

SAP Error Message - Details

• Message type: E = Error

• Message class: DA - Dictionary: Compare, distribution, timer, instantiation

• Message number: 661

• Message text: Non-supported type change for table &1

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message DA661 - Non-supported type change for table &1 ?

  The SAP error message DA661, which states "Non-supported type change for table &1," typically occurs when there is an attempt to change the data type of a field in a database table that is not allowed due to various constraints. This can happen during a modification of a table structure, such as when you are trying to change a field from one data type to another that is incompatible.
  Causes:
  
  Incompatible Data Type Change: The most common cause is trying to change a field's data type to one that is not compatible with the existing data or structure.
  Foreign Key Constraints: If the field is part of a foreign key relationship, changing its type may violate referential integrity.
  Data Dictionary Restrictions: SAP has certain restrictions on how data types can be changed in the Data Dictionary (DDIC).
  Existing Data: If there is existing data in the table that cannot be converted to the new data type, this will also trigger the error.
  
  Solutions:
  
  Check Compatibility: Review the data types involved and ensure that the change you are trying to make is compatible. For example, changing from CHAR to INT directly is not allowed.
  Create a New Field: Instead of changing the existing field, consider creating a new field with the desired data type and then migrating the data from the old field to the new one.
  Adjust Foreign Key Relationships: If the field is part of a foreign key, you may need to drop the foreign key constraint before making the change and then re-establish it afterward.
  Data Migration: If you need to change the data type, you may need to export the data, drop the table, recreate it with the new structure, and then import the data back.
  Use a Transport Request: If the change is part of a development project, ensure that it is included in a transport request and that all dependencies are managed properly.
  
  Related Information:
  
  SAP Notes: Check SAP Notes for any specific guidance or updates related to this error message. SAP frequently updates its documentation and may have specific notes addressing this issue.
  Data Dictionary (SE11): Use transaction SE11 to view the table structure and analyze the fields and their data types.
  Database Constraints: Review any constraints on the table that may prevent the change.
  Testing: Always test changes in a development or quality assurance environment before applying them to production.
  
  If you continue to face issues, consider reaching out to your SAP Basis or ABAP team for further assistance, as they may have more insights into the specific configurations and constraints of your SAP environment.