How To Fix DT315 - Text foreign key for table & is already defined:

DT315 - Overview

• Message type: E = Error

• Message class: DT - Table activation (incl. indexes)

• Message number: 315

• Message text: Text foreign key for table & is already defined:

What causes this issue?

There is usually only one text table for a check table.
In this case, a text foreign key which already has more foreign keys
was defined for a check table.
The text tables which already exist are listed in the next log lines.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Check whether this table or the listed text tables are really a text
table for the check table.
If several text tables were defined, this can result in problems if
text for a table is automatically read.
This is true for example for the possible values function and when
generating maintenance views.

Error message extract from SAP system. Copyright SAP SE.

DT315 - Details

• The SAP error message DT315 indicates that there is an issue with the foreign key definition for a specific table in the Data Dictionary (DDIC). This error typically arises when you attempt to define a foreign key relationship that already exists for the specified table.
  
  Cause:
  
  Duplicate Foreign Key Definition: The most common cause of this error is that a foreign key relationship for the specified table has already been defined in the Data Dictionary. This can happen if you or someone else has already created a foreign key with the same name or for the same fields.
  Inconsistent Data Dictionary: Sometimes, inconsistencies in the Data Dictionary can lead to this error, especially if changes were made directly in the database or if there were issues during transport.
  
  
  Solution:
  
  
  Check Existing Foreign Keys:
  
  Go to the Data Dictionary (transaction SE11).
  Enter the table name that is causing the error and display its details.
  Navigate to the "Foreign Keys"