How To Fix OL387 - Only ABAP data types C, N, D and T are permitted as key fields

SAP Error Message - Details

• Message type: E = Error

• Message class: OL - Workflow object types: Run-time system

• Message number: 387

• Message text: Only ABAP data types C, N, D and T are permitted as key fields

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message OL387 - Only ABAP data types C, N, D and T are permitted as key fields ?

  The SAP error message OL387 indicates that you are trying to use a data type that is not permitted as a key field in a certain context, such as when defining a table or a structure in ABAP. The only allowed data types for key fields in this context are:
  
  C: Character
  N: Numeric
  D: Date
  T: Time
  
  Cause
  This error typically occurs when you attempt to define a key field using a data type that is not one of the permitted types listed above. Common causes include:
  
  Using Unsupported Data Types: Attempting to use data types like STRING, XSTRING, FLOAT, or any other non-permitted type as a key field.
  Incorrect Field Definition: Defining a field in a structure or table that is intended to be a key field but does not conform to the allowed data types.
  
  Solution
  To resolve the OL387 error, you should:
  
  
  Check Data Types: Review the data types of the fields you are trying to use as key fields. Ensure that they are one of the permitted types (C, N, D, T).
  
  
  Modify Field Definitions: If you find that you are using an unsupported data type, change the data type of the field to one of the allowed types. For example:
  
  If you are using a STRING, consider changing it to a CHAR (C) with a defined length.
  If you are using a FLOAT, consider using a numeric type (N) if appropriate.
  
  
  
  Review Table/Structure Design: Ensure that the overall design of your table or structure aligns with SAP's requirements for key fields.
  
  
  Related Information
  
  ABAP Data Types: Familiarize yourself with the different ABAP data types and their characteristics. The official SAP documentation provides detailed information on data types and their usage.
  Key Fields in Database Tables: Understand the role of key fields in database tables and how they are used for indexing and data retrieval.
  SAP Community and Forums: If you continue to face issues, consider reaching out to the SAP community or forums for additional support and insights from other developers who may have encountered similar issues.
  
  By ensuring that your key fields conform to the allowed data types, you should be able to resolve the OL387 error and proceed with your development work in SAP.