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Description

This error indicates that an `ALTER TABLE` operation attempted to rename a column that is actively participating in a foreign key constraint. MariaDB prevents such operations to maintain data integrity and prevent orphaned references between tables.

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Error Message

Columns participating in a foreign key are renamed

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Known Causes

4 known causes

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Direct Column Rename Attempt

An `ALTER TABLE RENAME COLUMN` statement was executed directly on a column that is defined as part of a foreign key constraint.

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Renaming Referenced Primary Key

Attempting to rename a primary key column in the parent table, where this column is referenced by one or more foreign keys in child tables.

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Automated Schema Migration

A schema migration tool or script attempted to rename a foreign key column as part of a larger database update, failing due to the underlying constraint.

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Schema Misunderstanding/Typo

The user or script attempted to rename a column, unaware that it was part of a foreign key, possibly due to a typo or incomplete understanding of the database schema.

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Solutions

3 solutions available

1. Recreate Foreign Key Constraint medium

Drop and re-add the foreign key constraint after renaming columns.

1

Identify the foreign key constraint that is causing the error. You can find this information by querying the `INFORMATION_SCHEMA.KEY_COLUMN_USAGE` table.

SELECT CONSTRAINT_NAME, REFERENCED_TABLE_NAME, REFERENCED_COLUMN_NAME, COLUMN_NAME FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE TABLE_SCHEMA = 'your_database_name' AND REFERENCED_TABLE_NAME IS NOT NULL;

2

Drop the existing foreign key constraint. Replace `fk_constraint_name` with the actual name of your foreign key constraint.

ALTER TABLE your_table_name DROP FOREIGN KEY fk_constraint_name;

3

Rename the columns in both the referencing and referenced tables to their desired names.

ALTER TABLE your_table_name CHANGE old_column_name new_column_name data_type;
ALTER TABLE referenced_table_name CHANGE old_referenced_column_name new_referenced_column_name data_type;

4

Re-add the foreign key constraint using the new column names. Make sure to specify the correct data types for the columns.

ALTER TABLE your_table_name ADD CONSTRAINT fk_constraint_name FOREIGN KEY (new_column_name) REFERENCES referenced_table_name (new_referenced_column_name) ON DELETE CASCADE ON UPDATE CASCADE;

2. Modify Column Names and Recreate Constraint medium

Rename columns and then recreate the foreign key constraint in one go.

1

Identify the foreign key constraint and the involved tables and columns. Use `INFORMATION_SCHEMA.KEY_COLUMN_USAGE` if unsure.

SELECT CONSTRAINT_NAME, TABLE_NAME, COLUMN_NAME, REFERENCED_TABLE_NAME, REFERENCED_COLUMN_NAME FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE TABLE_SCHEMA = 'your_database_name' AND REFERENCED_TABLE_NAME IS NOT NULL;

2

Rename the columns in the referencing table. Replace `your_table_name`, `old_column_name`, `new_column_name`, and `data_type` accordingly.

ALTER TABLE your_table_name CHANGE old_column_name new_column_name data_type;

3

Rename the columns in the referenced table. Replace `referenced_table_name`, `old_referenced_column_name`, `new_referenced_column_name`, and `data_type` accordingly.

ALTER TABLE referenced_table_name CHANGE old_referenced_column_name new_referenced_column_name data_type;

4

Drop the foreign key constraint using its name.

ALTER TABLE your_table_name DROP FOREIGN KEY fk_constraint_name;

5

Re-add the foreign key constraint with the newly renamed columns. Adjust `ON DELETE` and `ON UPDATE` actions as needed.

ALTER TABLE your_table_name ADD CONSTRAINT fk_constraint_name FOREIGN KEY (new_column_name) REFERENCES referenced_table_name (new_referenced_column_name) ON DELETE RESTRICT ON UPDATE NO ACTION;

3. Use a Script for Bulk Renaming and Constraint Management advanced

Automate the process of renaming columns and recreating foreign keys across multiple constraints.

1

Generate a script that queries `INFORMATION_SCHEMA.KEY_COLUMN_USAGE` to identify all foreign key constraints and their associated columns.

SELECT CONCAT('ALTER TABLE `', TABLE_NAME, '` CHANGE `', COLUMN_NAME, '` `', COLUMN_NAME, '_new` ', DATA_TYPE, ';') AS rename_statement_referencing, CONCAT('ALTER TABLE `', REFERENCED_TABLE_NAME, '` CHANGE `', REFERENCED_COLUMN_NAME, '` `', REFERENCED_COLUMN_NAME, '_new` ', REFERENCED_DATA_TYPE, ';') AS rename_statement_referenced, CONCAT('ALTER TABLE `', TABLE_NAME, '` DROP FOREIGN KEY `', CONSTRAINT_NAME, '`;') AS drop_fk_statement, CONCAT('ALTER TABLE `', TABLE_NAME, '` ADD CONSTRAINT `', CONSTRAINT_NAME, '` FOREIGN KEY (`', COLUMN_NAME, '_new`) REFERENCES `', REFERENCED_TABLE_NAME, '` (`', REFERENCED_COLUMN_NAME, '_new`) ON DELETE ', ON_DELETE, ' ON UPDATE ', ON_UPDATE, ';') AS add_fk_statement FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE kcu JOIN INFORMATION_SCHEMA.COLUMNS c1 ON kcu.TABLE_SCHEMA = c1.TABLE_SCHEMA AND kcu.TABLE_NAME = c1.TABLE_NAME AND kcu.COLUMN_NAME = c1.COLUMN_NAME JOIN INFORMATION_SCHEMA.COLUMNS c2 ON kcu.TABLE_SCHEMA = c2.TABLE_SCHEMA AND kcu.REFERENCED_TABLE_NAME = c2.TABLE_NAME AND kcu.REFERENCED_COLUMN_NAME = c2.COLUMN_NAME WHERE kcu.TABLE_SCHEMA = 'your_database_name' AND kcu.REFERENCED_TABLE_NAME IS NOT NULL AND kcu.CONSTRAINT_TYPE = 'FOREIGN KEY';

2

Execute the generated SQL statements to rename columns, drop foreign keys, and then re-add them with the new column names. It's highly recommended to back up your database before running such a script.

# This is a conceptual example. You would typically save the output of the query above into a file and then execute it.
# Example of executing commands from a file:
bash
mysql -u your_user -p your_database_name < rename_and_recreate_fk.sql

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Related Errors

5 related errors

MariaDB Error 1849: Foreign Key Column Rename