If you haven’t created the child table you can run the following SQL command:
CREATE TABLE ChildTable (
ChildID INT PRIMARY KEY AUTO_INCREMENT,
ParentID INT,
ChildFields VARCHAR(255),
-- Add fields as required
-- Define the foreign key and the cascade rule
FOREIGN KEY (ParentID)
REFERENCES ParentTable(ParentID)
ON DELETE CASCADE
);
If you have already created the Child Table you can run an alter statement:
ALTER TABLE ChildTable
ADD CONSTRAINT fk_ParentTable_link
FOREIGN KEY (ParentID)
REFERENCES ParentTable(ParentID)
ON DELETE CASCADE;
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