SQL - LIKE WITH WILDCARD OPERATORS

LIKE Clause:

The SQL LIKE clause is used to compare a value to similar values using wildcard operators. There are two wildcards used in conjunction with the LIKE operator:

·      The percent sign (%)

·      The underscore (_)

The percent sign represents zero, one, or multiple characters. The underscore represents a single number or character. The symbols can be used in combinations.

Syntax:

The basic syntax of % and _ is as follows:

SELECT FROM table_name

WHERE column LIKE 'XXXX%'

or

SELECT FROM table_name

WHERE column LIKE '%XXXX%'

or

SELECT FROM table_name

WHERE column LIKE 'XXXX_'

or

SELECT FROM table_name

WHERE column LIKE '_XXXX'

or

SELECT FROM table_name

WHERE column LIKE '_XXXX_'

You can combine N number of conditions using AND or OR operators. Here, XXXX could be any numeric or string value.

Example:

Here are number of examples showing WHERE part having different LIKE clause with '%' and '_' operators:

Statement	Description
WHERE SALARY LIKE '200%'	Finds any values that start with 200
WHERE SALARY LIKE '%200%'	Finds any values that have 200 in any position
WHERE SALARY LIKE '_00%'	Finds any values that have 00 in the second and third positions
WHERE SALARY LIKE '2_%_%'	Finds any values that start with 2 and are at least 3 characters in length
WHERE SALARY LIKE '%2'	Finds any values that end with 2
WHERE SALARY LIKE '_2%3'	Finds any values that have a 2 in the second position and end with a 3
WHERE SALARY LIKE '2___3'	Finds any values in a five-digit number that start with 2 and end with 3

Let us take a real example, consider the CUSTOMERS table having the following records:

Following is an example, which would display all the records from CUSTOMERS table where LASTNAME  starts with Gowda:

SELECT * FROM CUSTOMER

WHERE lastname LIKE 'Gowda';

SELECT * FROM CUSTOMER

WHERE lastname LIKE 'P%';

SELECT * FROM CUSTOMER

WHERE country LIKE '__d%';

SELECT * FROM CUSTOMER

WHERE lastname LIKE '%r';