Documentation for SQL Code

The following documentation explains the purpose and functionality of each section and statement in the provided SQL code.

Section 1: Creating Tables

Statement 1: CREATE TABLE Employees

This statement creates a table called "Employees" with the following columns:

• employee_id: primary key for identifying employees
• first_name: first name of the employee
• last_name: last name of the employee
• salary: salary of the employee

Statement 2: CREATE TABLE Departments

This statement creates a table called "Departments" with the following columns:

• department_id: primary key for identifying departments
• department_name: name of the department

Section 2: Inserting Data

Statement 3: INSERT INTO Employees

This statement inserts data into the "Employees" table. It specifies the values for each column for a new record to be inserted into the table.

Statement 4: INSERT INTO Departments

This statement inserts data into the "Departments" table. It specifies the values for each column for a new record to be inserted into the table.

Section 3: Updating Data

Statement 5: UPDATE Employees

This statement updates the salary of employees in the "Employees" table. It sets the new salary based on a condition specified in the WHERE clause.

Section 4: Deleting Data

Statement 6: DELETE FROM Employees

This statement deletes records from the "Employees" table based on a condition specified in the WHERE clause.

Section 5: Querying Data

Statement 7: SELECT * FROM Employees

This statement retrieves all the records from the "Employees" table.

Statement 8: SELECT * FROM Departments

This statement retrieves all the records from the "Departments" table.

Conclusion

The provided SQL code creates tables, inserts data into them, updates the data, deletes data, and retrieves it. These statements are used to manipulate and query data in the "Employees" and "Departments" tables.