Using the LIKE Operator in SQL

In many situations you search for records in your database whose exact values are unknown. Using the LIKE operator along with a character pattern (search string) you can easily find the match. The character pattern is constructed with the help of two special characters: % and _. The percent character (%) represents zero or more characters, while the underscore character (_) represents just one. The first example below searches all employees starting with the letter ‘A’. The second statement displays a list of all employees who do not contain ‘a’ within their names. The third example searches for employees whose first name has an ‘a’ as the second letter.

NOTE

Some DBMS are case sensitive, therefore you must take care of it while using the LIKE operator. For example, such DBMS would treat 'adam' and 'Adam' differently. Microsoft Access uses * instead of % and ? instead of _.

    SQL Statement :

SELECT       first_name

FROM          employees

WHERE      first_name LIKE ‘A%’;

    Output :

    SQL Statement :

SELECT       first_name

FROM          employees

WHERE       first_name NOT LIKE ‘%a%’;

    Output :

    SQL Statement :

SELECT       first_name

FROM          employees

WHERE       first_name LIKE ‘_a%’;

    Output :