How To Fix AD303 - Foreign key &-& (enter valid cardinality)

SAP Error Message - Details

• Message type: E = Error

• Message class: AD - Data Dictionary application messages

• Message number: 303

• Message text: Foreign key &-& (enter valid cardinality)

What causes this issue?

You have defined a semantic foreign key without specifying the
cardinality.

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?

Enter the cardinality. The following cardinalities are possible:
<LS>C</> A record of the check table may be referenced by at most one
dependent record.
<LS>1</> Each record of the check table is referenced by exactly one
dependent record.
<LS>CN</> A record of the check table is referenced by any number of
dependent records.
<LS>N</> A record of the check table is referenced by at least one
dependent record.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message AD303 - Foreign key &-& (enter valid cardinality) ?

  The SAP error message AD303, which states "Foreign key &-& (enter valid cardinality)," typically occurs when there is an issue with the definition of a foreign key relationship in the data dictionary. This error indicates that the cardinality defined for the foreign key is not valid or does not match the expected values.
  Cause:
  
  Invalid Cardinality Definition: The cardinality of the foreign key relationship is not correctly defined. Cardinality refers to the nature of the relationship between two tables, such as one-to-one, one-to-many, or many-to-many.
  Mismatch in Data Types: The data types of the foreign key and the primary key do not match, which can lead to issues in establishing a valid relationship.
  Missing or Incorrectly Defined Foreign Key: The foreign key may not be properly defined in the database schema, or it may be referencing a non-existent primary key.
  Inconsistent Table Relationships: The relationships between tables may not be consistent, leading to ambiguity in how records are related.
  
  Solution:
  
  Check Cardinality Settings: Review the cardinality settings in the data dictionary for the foreign key. Ensure that they are set correctly according to the intended relationship between the tables.
  Verify Data Types: Ensure that the data types of the foreign key and the corresponding primary key match. If they do not, adjust them accordingly.
  Define Foreign Key Properly: If the foreign key is not defined, or if it is defined incorrectly, redefine it in the data dictionary. Make sure it references the correct primary key in the related table.
  Use Transaction Codes: Use transaction codes like SE11 (Data Dictionary) to check and modify the table definitions and relationships.
  Check for Existing Data: If there is existing data in the tables, ensure that it adheres to the defined foreign key constraints. You may need to clean up the data if it violates the constraints.
  
  Related Information:
  
  
  Cardinality Types: Understand the different types of cardinality:
  
  One-to-One (1:1)
  One-to-Many (1:N)
  Many-to-One (N:1)
  Many-to-Many (N:N)
  
  
  
  Data Dictionary (SE11): Familiarize yourself with the SAP Data Dictionary (SE11) to manage and define database objects, including tables, views, and relationships.
  
  
  Foreign Key Constraints: Review the concept of foreign key constraints in relational databases to understand how they enforce referential integrity.
  
  
  SAP Notes and Documentation: Check SAP Notes and official documentation for any specific guidance or updates related to this error message.
  
  
  By following these steps, you should be able to resolve the AD303 error and ensure that your foreign key relationships are correctly defined in your SAP system.