What causes ORA-00001?

Pipeline inserts data that was already loaded in a prior run (no deduplication logic). Target table has a unique constraint the source data does not enforce. Parallel pipeline branches write the same key simultaneously. Incorrect MERGE or UPSERT logic leaves duplicate rows

How do I fix ORA-00001?

Step 1: Identify the constraint: `SELECT constraint_name, constraint_type FROM user_constraints WHERE table_name = ' ';`.. Step 2: Find the duplicate key in the error message and trace it back to the source.. Step 3: Add deduplication (e.g. `ROW_NUMBER() OVER (PARTITION BY key ORDER BY updated_at DESC) = 1`) before the load.. Step 4: Switch to a MERGE statement to handle updates vs. inserts correctly.. Step 5: If this is a re-run scenario, truncate or soft-delete the previous data before re-inserting.

High severitydata

Oracle Database Error:
ORA-00001

What does this error mean?

A row was inserted or updated with a value that duplicates an existing entry in a column or combination of columns that has a UNIQUE or PRIMARY KEY constraint.

Common causes

1Pipeline inserts data that was already loaded in a prior run (no deduplication logic)
2Target table has a unique constraint the source data does not enforce
3Parallel pipeline branches write the same key simultaneously
4Incorrect MERGE or UPSERT logic leaves duplicate rows

How to fix it

1Step 1: Identify the constraint: `SELECT constraint_name, constraint_type FROM user_constraints WHERE table_name = '<TABLE>';`.
2Step 2: Find the duplicate key in the error message and trace it back to the source.
3Step 3: Add deduplication (e.g. `ROW_NUMBER() OVER (PARTITION BY key ORDER BY updated_at DESC) = 1`) before the load.
4Step 4: Switch to a MERGE statement to handle updates vs. inserts correctly.
5Step 5: If this is a re-run scenario, truncate or soft-delete the previous data before re-inserting.

Example log output

ORA-00001: unique constraint (SCHEMA.PK_ORDERS) violated
ADF: UserErrorOdbcOperationFailed - The following error occurred while writing to Oracle: ORA-00001

Frequently asked questions

How do I find which row caused ORA-00001?

The error message includes the constraint name. Query `user_constraints` and `user_cons_columns` to find the column, then search for duplicates in the source data.

Source · docs.oracle.com/error-help/db/ora-00001