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Description

Error 294, ERR_SQL_MANY_PRIMARY_KEY, indicates an attempt to define or modify a database table with more than one primary key constraint. This typically occurs during schema creation, data model changes, or when importing table definitions into SAP S/4HANA's underlying database.

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Error Message

Cannot have more than one primary key

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Known Causes

3 known causes

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Incorrect SQL Script

An SQL script or database migration tool attempted to create or alter a table definition with multiple PRIMARY KEY constraints in its DDL.

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ABAP Dictionary Misconfiguration

A table definition in the ABAP Dictionary was incorrectly configured, leading to the generation of SQL that violates the single primary key rule.

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External Tool Conflict

An external data migration or schema synchronization tool generated conflicting table definitions, attempting to assign multiple primary keys.

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Solutions

3 solutions available

1. Identify and Remove Duplicate Primary Key Definitions medium

Locate and eliminate redundant primary key constraints in your S/4HANA system.

1

Connect to your SAP S/4HANA system's database using a suitable SQL client (e.g., SAP HANA Studio, hdbsql).

2

Query the system catalog views to identify tables with multiple primary key definitions. The exact view might vary slightly depending on your HANA version, but `CONSTRAINTS` or similar views are common.

SELECT SCHEMA_NAME, TABLE_NAME, CONSTRAINT_NAME, CONSTRAINT_TYPE
FROM "SYS"."CONSTRAINTS"
WHERE CONSTRAINT_TYPE = 'PRIMARY KEY'
GROUP BY SCHEMA_NAME, TABLE_NAME, CONSTRAINT_NAME, CONSTRAINT_TYPE
HAVING COUNT(*) > 1;

3

Examine the output of the query. For each table identified, list all defined primary keys. You'll need to determine which one is the intended and correct primary key.

4

If multiple primary keys are found for the same table, you will need to drop the redundant ones. **Caution:** Ensure you understand the implications of dropping constraints, especially in a production environment. Always perform this in a test environment first.

ALTER TABLE "<schema_name>"."<table_name>" DROP CONSTRAINT "<redundant_pk_constraint_name>";

5

After dropping the redundant constraints, re-verify by running the query from step 2. The count for the affected table should now be 1.

2. Review and Correct Data Model Definitions advanced

Address the root cause by correcting the data model to ensure only one primary key is defined per table.

1

Identify the specific table causing the error. This might be evident from the error message or by analyzing the transaction/process that triggered it.

2

Access the Data Dictionary (SE11 in ABAP environment) or the equivalent HANA modeling tools (e.g., SAP HANA Studio, SAP Business Application Studio) for the relevant table.

3

Navigate to the 'Key Columns' or 'Primary Key' definition section for the table.

4

Carefully review the defined primary key. Ensure that only one set of columns is designated as the primary key. If multiple are present, remove the incorrect or redundant definitions.

5

Save the changes to the table definition. This might involve activating the Data Dictionary object in SE11 or generating/activating the model in HANA tools.

6

If this is a custom development, ensure that the development process adheres to best practices for defining primary keys.

3. Analyze and Recreate Table with Correct Primary Key advanced

For complex scenarios, consider recreating the table with the correct primary key definition.

1

Backup the existing table data. This is a critical step before any structural changes.

CREATE COLUMN TABLE "<schema_name>"."<table_name>_BACKUP" AS SELECT * FROM "<schema_name>"."<table_name>";

2

Drop the existing table that has the multiple primary key definitions.

DROP TABLE "<schema_name>"."<table_name>";

3

Create a new table definition with the correct, single primary key. Define all necessary columns, data types, and constraints.

CREATE COLUMN TABLE "<schema_name>"."<table_name>" (
    <column1> <datatype> NOT NULL,
    <column2> <datatype> NOT NULL,
    ...
    PRIMARY KEY (<primary_key_column1>, <primary_key_column2>)
);

4

Insert the data from the backup table into the newly created table.

INSERT INTO "<schema_name>"."<table_name>" SELECT * FROM "<schema_name>"."<table_name>_BACKUP";

5

Drop the backup table.

DROP TABLE "<schema_name>"."<table_name>_BACKUP";

6

Perform thorough testing to ensure data integrity and application functionality.

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Related Errors

5 related errors

SAP S/4HANA Error 294: Multiple Primary Keys