What is the purpose of the LIKE operator in SQL, and how do you use it?

The LIKE operator in SQL is used for pattern matching in string data. It allows you to search for a specified pattern within a column of text data. The LIKE operator is commonly used in conjunction with wildcard characters to perform flexible and partial string matching.

The two most commonly used wildcard characters with the LIKE operator are:

• '%' (percent sign): Matches any sequence of characters (including zero characters).
• '_' (underscore): Matches any single character.

Here's how to use the LIKE operator:

1. Using the % Wildcard:

• '% ' at the beginning and end of a pattern: This matches any string containing the specified pattern.

            SELECT * FROM table_name WHERE column_name LIKE '%pattern%';

• '%' at the beginning of a pattern: This matches any string ending with the specified pattern.

            SELECT * FROM table_name WHERE column_name LIKE '%pattern';

• '%' at the end of a pattern: This matches any string starting with the specified pattern.

            SELECT * FROM table_name WHERE column_name LIKE 'pattern%';

2. Using the _ Wildcard:

• '_' matches any single character, so you can use it to match a single character at a specific position.

            SELECT * FROM table_name WHERE column_name LIKE 'a_b';

            In these examples:

• table_name is the name of the table you're querying.
• column_name is the name of the column within the table where you want to search for the specified pattern.
• pattern is the string or pattern you want to search for.

Here are a few practical examples:

• To find all records in a "users" table where the "email" column contains the word "example" anywhere in the email address:

            SELECT * FROM users WHERE email LIKE '%example%';

• To find all records in a "products" table where the "product_name" column starts with the letter "A":

            SELECT * FROM products WHERE product_name LIKE 'A%';

• To find all records in a "customers" table where the "phone_number" column has the format "555-xxxx," where "x" can be any digit:

            SELECT * FROM customers WHERE phone_number LIKE '555-___';

The LIKE operator is versatile and useful for searching and filtering text data based on patterns, and it's widely used in SQL queries for various applications.