SQL Wildcards Tutorial

Example Table

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

    CREATE TABLE employees (
        employee_id INT PRIMARY KEY,
        name VARCHAR(50),
        department VARCHAR(50),
        salary DECIMAL(10, 2)
    );
    
    INSERT INTO employees (employee_id, name, department, salary) VALUES
    (1, 'Alice', 'HR', 50000.00),
    (2, 'Bob', 'IT', 60000.00),
    (3, 'Charlie', 'Finance', 55000.00),
    (4, 'David', 'IT', 62000.00),
    (5, 'Eve', 'HR', 48000.00);
    

Employees Table

employee_id	name	department	salary
1	Alice	HR	50000.00
2	Bob	IT	60000.00
3	Charlie	Finance	55000.00
4	David	IT	62000.00
5	Eve	HR	48000.00

Using SQL Wildcards

SQL wildcards are used with the LIKE operator to search for a specified pattern in a column.

Example: Using the Percent (%) Wildcard

To select employees whose names start with 'A':

    SELECT * FROM employees
    WHERE name LIKE 'A%';
    

Result:

Query	SELECT * FROM employees WHERE name LIKE 'A%';
Result	employee_id: 1, name: Alice, department: HR, salary: 50000.00

Example: Using the Underscore (_) Wildcard

To select employees whose names have 'a' as the second character:

    SELECT * FROM employees
    WHERE name LIKE '_a%';
    

Result:

Query	SELECT * FROM employees WHERE name LIKE '_a%';
Result	employee_id: 4, name: David, department: IT, salary: 62000.00

Example: Using the Brackets ([]) Wildcard

To select employees whose names start with 'A' or 'E':

    SELECT * FROM employees
    WHERE name LIKE '[AE]%';
    

Result:

Query	SELECT * FROM employees WHERE name LIKE '[AE]%';
Result	employee_id: 1, name: Alice, department: HR, salary: 50000.00 employee_id: 5, name: Eve, department: HR, salary: 48000.00