SQL Wildcards

-- select customers who live in countries
-- that start with 'US' followed by a single character
SELECT *
FROM Customers
WHERE country LIKE 'US_'

SQL Wildcard Syntax

The syntax of SQL Wildcards is:

SELECT column1, column 2, ... 
FROM table
WHERE column LIKE 'Wildcard String';

Here,

• column1, column2, ... are the columns to select the data from
• table is the name of the table
• column is the column we want to apply the filter to
• LIKE matches the column with Wildcard String
• Wildcard String is a combination of strings and wildcard characters

For example,

-- select rows where the last name
-- of customers start with R 
SELECT *
FROM Customers
WHERE last_name LIKE 'R%';

Here, % (zero or more characters) is a wildcard. So, 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 rows where the first names
-- of customers start with J 
SELECT *
FROM Customers
WHERE first_name LIKE 'J%';

Here, the SQL command selects customers whose last name starts with J 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 customers whose countries start with U
-- followed by a single character
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 customers with country that starts with UK or UA
-- and is followed by any number of characters

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 and any number of characters afterward.

! Wildcard in SQL

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

--select rows where customer's last names don't start with D or R
SELECT *
FROM Customers
WHERE last_name LIKE '[!DR]%';

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