Error
Error Code:
301
SAP S/4HANA Error 301: Unique Constraint Violated
Description
This error indicates an attempt to insert or update data that would violate a unique constraint in the SAP S/4HANA database. It typically occurs when a record with an identical value already exists for a field designated as unique, such as a primary key or unique index.
Error Message
ERR_SQL_UNIQUE_VIOLATED
Known Causes
4 known causesDuplicate Data Entry
A user or automated process attempted to create a new record with a value that already exists in a unique database field.
Integration Data Conflict
Data imported from an external system or API tried to insert a record with a non-unique value into a field requiring uniqueness.
Custom Logic Issue
Custom developments or configurations are generating or processing data in a way that leads to duplicate unique values.
Concurrent Record Creation
Multiple transactions or users simultaneously attempted to create records with the same unique identifier, with one succeeding and others failing.
Solutions
3 solutions available1. Investigate and Correct Duplicate Data medium
Identify and remove or modify the duplicate records causing the unique constraint violation.
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Identify the exact table and the unique key(s) that are being violated. This information is usually present in the detailed error logs or can be inferred from the context of the transaction that failed. You might need to consult SAP Notes related to the specific transaction or program that generated the error.
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Connect to your SAP S/4HANA database using a SQL client (e.g., SAP HANA Studio, DBVisualizer, or command-line tools).
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Write a SQL query to find duplicate entries in the identified table based on the unique key columns. Replace `your_table_name` and `column1`, `column2` with the actual table and column names.
SELECT column1, column2, COUNT(*) FROM your_table_name GROUP BY column1, column2 HAVING COUNT(*) > 1;4
Analyze the results of the query. Determine which of the duplicate records is the 'correct' one or if both are erroneous. This often requires understanding the business logic and the data's origin.
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Based on your analysis, either delete the duplicate records or update them to be unique. **Caution:** Perform these operations in a test environment first and ensure you have proper backups. If the duplicates were inserted by a specific SAP transaction, it's crucial to understand why it allowed duplicates and address the root cause within SAP.
DELETE FROM your_table_name WHERE primary_key_column = 'duplicate_value';
-- OR --
UPDATE your_table_name SET column_to_update = 'new_unique_value' WHERE primary_key_column = 'existing_value';6
Retry the SAP transaction that previously failed.
text2. Review and Adjust SAP Application Logic advanced
Examine the SAP program or transaction logic to prevent duplicate data insertion.
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Identify the SAP transaction code (T-code) or the ABAP program that is attempting to insert the data causing the unique constraint violation. This can be found in the S/4HANA application logs or by debugging the process.
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Consult with an SAP functional or ABAP consultant to review the application logic. They need to verify if there are proper checks in place to prevent duplicate entries before attempting to insert into the database table.
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If the application logic is indeed flawed, the ABAP consultant will need to implement necessary checks, such as SELECT statements to verify existence before INSERT, or utilize SAP standard functionalities for data validation.
Example ABAP snippet (conceptual):
IF NOT EXISTS (SELECT 1 FROM your_table_name WHERE column1 = input_value1 AND column2 = input_value2) THEN
INSERT INTO your_table_name (column1, column2, ...) VALUES (input_value1, input_value2, ...).
ENDIF.4
Thoroughly test the modified application logic in a development or quality assurance environment before deploying to production.
text3. Temporary Disabling of Unique Constraint (Use with Extreme Caution) advanced
Temporarily disable the unique constraint to allow data loading or migration, followed by re-enabling and data cleanup.
1
Identify the specific unique constraint that is causing the error. You can find this information in the database catalog or by inspecting the table definition.
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**This is a high-risk operation and should only be performed in a controlled environment with downtime considerations and proper authorization.** Disable the unique constraint. Replace `your_table_name` and `your_constraint_name` with actual names.
ALTER TABLE your_table_name DISABLE CONSTRAINT your_constraint_name;3
Proceed with the data loading or operation that was previously failing. This step now bypasses the unique constraint check.
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After the operation is complete, re-enable the unique constraint. This will fail if duplicates still exist.
ALTER TABLE your_table_name ENABLE CONSTRAINT your_constraint_name;5
If re-enabling the constraint fails, you will need to go back to 'Investigate and Correct Duplicate Data' to clean up the duplicates before you can re-enable the constraint.
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