SQL statement categories (DDL, DML, DQL, DCL) - Mini Project: Build & Apply

Understanding SQL Statement Categories: DDL, DML, DQL, DCL

📖 Scenario: You are working as a junior database assistant in a small company. Your manager wants you to organize and understand different types of SQL statements so that you can use them correctly when managing the company database.

🎯 Goal: Build a simple SQL script that categorizes example SQL statements into the four main categories: DDL, DML, DQL, and DCL. You will create tables, insert data, query data, and control access using the correct SQL commands for each category.

📋 What You'll Learn

Create a table using a DDL statement

Insert data into the table using a DML statement

Query data from the table using a DQL statement

Grant permission using a DCL statement

💡 Why This Matters

🌍 Real World

Organizing SQL statements into categories helps database administrators and developers understand how to manage data and structure safely and efficiently.

💼 Career

Knowing SQL categories is essential for roles like database administrators, backend developers, and data analysts to perform their tasks correctly.

1

Create a table using a DDL statement

Write a SQL statement to create a table called Employees with two columns: EmployeeID as an integer and Name as a variable character string of length 50. Use the correct DDL command.

SQL

-- Write the CREATE TABLE statement for Employees
-- Your code here

Need a hint?

DDL commands are used to define or change database structures. To create a table, use CREATE TABLE.

2

Insert data into the table using a DML statement

Write a SQL statement to insert a new employee with EmployeeID 1 and Name 'Alice' into the Employees table. Use the correct DML command.

SQL

CREATE TABLE Employees (
    EmployeeID INT,
    Name VARCHAR(50)
);
-- Write the INSERT statement to add Alice
-- Your code here

Need a hint?

DML commands are used to add or change data. To add a row, use INSERT INTO.

3

Query data from the table using a DQL statement

Write a SQL statement to select all columns and rows from the Employees table. Use the correct DQL command.

SQL

CREATE TABLE Employees (
    EmployeeID INT,
    Name VARCHAR(50)
);
INSERT INTO Employees (EmployeeID, Name) VALUES (1, 'Alice');
-- Write the SELECT statement to get all employees
-- Your code here

Need a hint?

DQL commands are used to read data. To get all data from a table, use SELECT * FROM.

4

Grant permission using a DCL statement

Write a SQL statement to grant SELECT permission on the Employees table to a user named guest_user. Use the correct DCL command.

SQL

CREATE TABLE Employees (
    EmployeeID INT,
    Name VARCHAR(50)
);
INSERT INTO Employees (EmployeeID, Name) VALUES (1, 'Alice');
SELECT * FROM Employees;
-- Write the GRANT statement to allow guest_user to SELECT
-- Your code here

Need a hint?

DCL commands control access. To give permission, use GRANT.