How can foreign keys be properly implemented in MySQL tables referencing multiple primary keys?

When implementing foreign keys in MySQL tables referencing multiple primary keys, you can use a composite key in the child table that includes all the primary keys from the parent table. This ensures that each combination of primary keys in the parent table has a corresponding reference in the child table.

CREATE TABLE parent_table (
    primary_key1 INT,
    primary_key2 INT,
    PRIMARY KEY (primary_key1, primary_key2)
);

CREATE TABLE child_table (
    primary_key1 INT,
    primary_key2 INT,
    FOREIGN KEY (primary_key1, primary_key2) REFERENCES parent_table(primary_key1, primary_key2)
);