-
Written By Lovely Baghel
-
Approved By Mithilesh Tata
-
Updated on February 18th, 2025
-
Reading Time: 5 minutes
Summary: The IT enthusiast worries about SQL database errors because they frequently interfere with operations. MS SQL becomes the core upon which the major operations of organizations are carried out. Error Code 1451 in MySQL indicates a violation of the foreign key constraint. This is caused by the failure to delete or update a record when other records exist in another table. In this blog, we will see why this error occurs and also fix error code 1451. We will give both manual procedures and recommend professional MySQL Database Recovery Software for easy resolution. Download Now Purchase Now
SQL Error 1451 arises due to several reasons. The most common reasons for the error are discussed below.
These are the common causes that lead to database errors.
To fix the SQL database error, we perform various methods, including manual methods and professional methods. Perform each method with caution to reduce any chance of data loss or data breach.
When encountering MySQL Error Code 1451, there are several manual methods you can apply to resolve the issue. Follow the below-mentioned steps to fix the MySQL error:
Look at the foreign key constraints causing the error and identify the relationship between the tables. Make sure you are not trying to delete or update a record that has a foreign key in another table.
Steps:
SHOW CREATE TABLE child_table; Using this, you can show you the FOREIGN KEY constraints and the columns. |
SELECT * FROM information_schema.KEY_COLUMN_USAGE WHERE TABLE_NAME = ‘child_table’ AND CONSTRAINT_NAME != ‘PRIMARY’; |
Resolution: Once you’ve identified the constraint, you can take appropriate action.
If you have a parent record to delete or update, the child table also refers to the parent record with a foreign key. You’ll need to either delete or update the dependent record first to fix error 1451.
Steps:
SELECT * FROM order_items WHERE order_id = <id_of_order_to_delete>; |
DELETE FROM order_items WHERE order_id = <id_of_order_to_delete>; |
UPDATE order_items SET order_id = NULL WHERE order_id = <id_of_order_to_delete>; |
Resolution: You can now proceed to delete or update the parent row since no dependent records remain that reference it.
In this method, you can modify the foreign key to automatically manage the deletion or update of the child records. Here, you can use the foreign key constraint with either ON DELETE CASCADE or ON UPDATE CASCADE.
Steps:
ALTER TABLE child_tableDROP FOREIGN KEY fk_constraint_name; |
ALTER TABLE child_tableADD CONSTRAINT fk_constraint_nameFOREIGN KEY (column_name)REFERENCES parent_table (column_name) |
Resolution: After this modification, you can delete or update the parent records without getting the error message of the foreign key constraint.
In case orphaned data exists due to a foreign key violation, it may be necessary to clean up the orphaned data manually. Thus, ensuring all child records are consistent with their parent records.
Steps:
SELECT * FROM child_table WHERE parent_id NOT IN (SELECT id FROM parent_table); |
DELETE FROM child_table WHERE parent_id NOT IN (SELECT id FROM parent_table); |
Resolution: After cleaning up orphaned records, the foreign key constraints should no longer cause violations. So, you will be able to perform your delete or update without running into Error 1451.
After successfully removing the foreign key violation, you will be able to create an MDF file. But sometimes, due to various reasons, the MDF file gets corrupted and becomes inaccessible. In such a scenario, MySQL Database Recovery software may assist you. The SQL Recovery software rectifies all problems in a corrupted database file to restore an operative database instead of a damaged file. By using this tool, you can restore all your database items, such as tables, views, triggers, table properties, etc. Besides this, it also allows users to Fix SQLite Database is Locked Error.
Here, we have analyzed the causes that come up with error code 1451 in MySQL. The error can be rectified by the manual procedures that have been above discussed. These manual procedures rectify ERROR 1451. In addition, these procedures are not appropriate for all users and are not effective each time. So you can straight away opt for a professional solution to fix Error Code 1451 and recover the database files corruption.
About The Author:
As a Technical expert, I love to write blogs on email migration, data recovery, and cloud migration. In my free time, I like to research new things related to technology.
Related Post