SQL Wildcards

A wildcard character in SQL is used with the LIKE clause to replace a single or set of characters in any string. For example,

SELECT *
FROM Customers
WHERE last_name LIKE 'R%';

Here, % (means zero or more characters) is a wildcard character. Hence, the SQL command selects customers whose last_name starts with R followed by zero or more characters after it.

Recommended Reading: SQL LIKE Operator

% Wildcard in SQL

The % wildcard in SQL is used to represent zero or more characters. For example,

SELECT *
FROM Customers
WHERE last_name LIKE 'R%';

Here, the SQL command selects customers whose last name starts with R followed by zero or more characters.

_ Wildcard in SQL

The _ wildcard in SQL is used to represent exactly one character in a string. For example,

SELECT *
FROM Customers
WHERE country LIKE 'U_';

Here, the SQL command selects customers whose country name starts with U and is followed by only one character.

[] Wildcard in SQL

The [] wildcard in SQL is used to represent any one character inside brackets. For example,

SELECT *
FROM Customers
WHERE country LIKE 'U[KA]%';

Here, the SQL command selects customers whose country name starts with U and is followed by either K or A. Any number of characters are allowed afterwards.

! Wildcard in SQL

The ! wildcard in SQL is used to exclude characters from a string. For example,

SELECT *
FROM Customers
WHERE last_name LIKE '[!DR]%';

Here, the SQL command selects customers whose last_name does not start with D or R.

Wildcard Characters in Different Databases

Different databases have different sets of wildcard characters. Some of them are listed here.