Wildcards - (MySQL Misc)

Wildcards in MySQL (and SQL in general) are special characters that are used to represent one or more other characters. They are used in conjunction with the LIKE operator in SQL queries to match patterns in string data.

Syntax

The two most commonly used wildcards in MySQL are the percent sign (%) and underscore (_) characters. The percent sign represents zero or more characters, while the underscore represents a single character.

Here is the basic syntax for using wildcards with the LIKE operator:

SELECT column_name FROM table_name WHERE column_name LIKE 'pattern';

The pattern parameter can include one or both of the wildcards.

Example

Let's say we have a table called users with columns for id, name, and email. We can use the LIKE operator with wildcards to search for users whose email address ends in "gmail.com" like this:

SELECT * FROM users WHERE email LIKE '%gmail.com';

This will return all records where the email column ends in "gmail.com".

Output

When we run the example above, the output will be all the records from the users table whose email address ends in "gmail.com".

Explanation

In the example above, we used the % wildcard to match zero or more characters in the email address. The LIKE operator then matched all records where the email column ended with "gmail.com".

Use

Wildcards are useful for searching for specific patterns in text data. They can be used to search for patterns such as email addresses, URLs, or phone numbers.

Important Points

• The percent sign (%) wildcard matches zero or more characters.
• The underscore (_) wildcard matches a single character.
• Wildcards can be used with the LIKE operator in SQL queries.
• Wildcards are useful for searching for specific patterns in text data.

Summary

In this tutorial, we discussed the use of wildcards in MySQL queries. We covered the syntax, example, output, explanation, use, and important points of wildcards in MySQL. With this knowledge, you can now use wildcards in your own MySQL queries to search for specific patterns in text data.