Explain referential integrity, the relationship between employees and departments, and how to implement a many-to-many relationship in a database, including an SQL DDL query.

You're on a roll — 1.b) Database Schema i) Explain the term referential integrity using the database schema above. Referential integrity ensures that relationships between tables remain consistent. In the given schema, dptmID in the Employee table is a foreign key referencing dptmID (primary key) in the Department table. Referential integrity means that every dptmID value in the Employee table must exist as a dptmID in the Department table, preventing employees from being assigned to non-existent departments. ii) State the type of relationship that exists between the employees and the departments entities? Given that an employee can work in more than one department, and a department may have several employees, the relationship is Many-to-Many. Many-to-Many iii) Briefly explain how this type of relationship could be implemented in a database. A Many-to-Many relationship is implemented using an associative table (also known as a junction or bridge table). This new table contains the primary keys of both related entities (Employee and Department) as foreign keys, forming a composite primary key for the associative table. iv) Write an SQL DDL query to create an associative table for this database called empDepmt including its key fields. `sql CREATE TABLE empDepmt ( empID INT NOT NULL, dptmID INT NOT NULL, PRIMARY KEY (empID, dptmID), FOREIGN KEY (empID) REFERENCES Employee(empID), FOREIGN KEY (dptmID) REFERENCES Department(dptmID) ); ` See SQL DDL query above Got more? Send 'em!