SQL SELECT Statement Tutorial

Example Table

We will use the following table named employees for our examples:

    CREATE TABLE employees (
        employee_id INT PRIMARY KEY,
        first_name VARCHAR(50),
        last_name VARCHAR(50),
        department VARCHAR(50),
        salary DECIMAL(10, 2)
    );

    INSERT INTO employees (employee_id, first_name, last_name, department, salary) VALUES
    (1, 'John', 'Doe', 'HR', 50000.00),
    (2, 'Jane', 'Smith', 'Finance', 60000.00),
    (3, 'Emily', 'Jones', 'IT', 70000.00),
    (4, 'Michael', 'Brown', 'IT', 80000.00),
    (5, 'Sarah', 'Davis', 'Finance', 55000.00);
    

Employees Table

employee_id	first_name	last_name	department	salary
1	John	Doe	HR	50000.00
2	Jane	Smith	Finance	60000.00
3	Emily	Jones	IT	70000.00
4	Michael	Brown	IT	80000.00
5	Sarah	Davis	Finance	55000.00

Using SQL SELECT Statement

The SELECT statement is used to select data from a database. The data returned is stored in a result table, sometimes called the result set.

Example: Selecting All Columns

To select all columns from the employees table:

    SELECT * FROM employees;
    

Result:

Query	SELECT * FROM employees;
Result	Returns all columns and rows from the employees table.

Example: Selecting Specific Columns

To select specific columns, such as first_name and last_name:

    SELECT first_name, last_name FROM employees;
    

Result:

Query	SELECT first_name, last_name FROM employees;
Result	Returns the first_name and last_name columns from the employees table.

Example: Using WHERE Clause

To select employees from the IT department:

    SELECT * FROM employees WHERE department = 'IT';
    

Result:

Query	SELECT * FROM employees WHERE department = 'IT';
Result	Returns all columns for employees in the IT department.

Example: Using ORDER BY Clause

To select all employees and order the result by salary in descending order:

    SELECT * FROM employees ORDER BY salary DESC;
    

Result:

Query	SELECT * FROM employees ORDER BY salary DESC;
Result	Returns all columns for employees ordered by salary in descending order.