When encountering the error "1219: Cannot update child row" in MySQL, it usually indicates a foreign key constraint failure. The immediate actions to take are:
SHOW ENGINE INNODB STATUS;
Look under the `LATEST FOREIGN KEY ERROR` section for details on the failed constraint.
SELECT TABLE
NAME, COLUMN
NAME, CONSTRAINT
NAME, REFERENCED
TABLE
NAME, REFERENCED
COLUMN_NAME
FROM INFORMATIONSCHEMA.KEY
COLUMN_USAGE
WHERE TABLENAME = 'your
child
table
name';
Replace `'yourchildtable_name'` with the name of the table you are attempting to update.
SELECT * FROM your
parent
table WHERE your
referenced
column = 'value
not
found';
Replace `yourparenttable`, `yourreferencedcolumn`, and `'valuenotfound'` with the appropriate table name, column name, and the value you're trying to insert/update in the child table, respectively.
5. If the parent row exists, ensure the value you're trying to insert/update in the child table matches exactly, including case sensitivity and data type, with the parent table's corresponding value.
(Perfect for DevOps & SREs)
(Perfect for DevOps & SREs)