Why Am I Getting a 'Foreign Key Constraint Violation' Error When Inserting Data?

Database integrity error: Detailed explanation of foreign key constraint conflict

You encountered an error while trying to insert data into the comments table. The error message "Integrity constraint violation: 1452 Cannot add or update a child row" indicates a problem with the foreign key constraint.

Understanding foreign key constraints

Foreign key constraints establish a relationship between two tables, ensuring that data in the child table matches the corresponding data in the parent table. In this example, the comments table has a foreign key constraint on the project_id column, which references the id column in the items table.

Error reason

The reason for the

error is that the project_id value you are trying to insert into the comments table does not exist in the items table. Specifically, the value '50dc845a-83e4-4db3-8705-5432ae7aaee3' does not match any id value in the project table.

Solution

To resolve this error, make sure the project_id value you insert into the comments table exists as a primary key in the items table. Validate the items table to identify the correct project_id and update your comments table accordingly.

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