Pattern Matching in SQL LIKE Operator

Syntax

SELECT * 
FROM table_name 
WHERE column_name LIKE pattern;

• *: All columns of the table
• table_name: Name of the table
• column_name: Name of the column to be searched
• LIKE: Keyword used for pattern matching
• pattern: The pattern to match

Example

Suppose we have a table named "employees" with columns "id", "name" and "salary". We want to find all the employees whose name starts with 'J'. The query for this is:

SELECT * 
FROM employees 
WHERE name LIKE 'J%';

Output

The query will return all the rows from the "employees" table whose name starts with 'J'.

Explanation

The LIKE operator is used for pattern matching in SQL. It is used to search for a match between the specified pattern and the column values. The '%' sign in the pattern specifies that any number of characters can be present after the specified letter. So, in the example above, the pattern 'J%' means any name that starts with 'J' and has any number of characters after that.

Use

The LIKE operator is useful when we want to search for a specific pattern in the column values. It is commonly used in the WHERE clause of a SQL query to filter out the rows based on a specific pattern.

Important Points

• The LIKE operator is not case-sensitive.
• The '%' sign in the pattern can be used to match zero or any number of characters.
• The '_' sign in the pattern can be used to match a single character.

Summary

The LIKE operator in SQL is used for pattern matching and allows us to search for a specific pattern in the column values. It can be used with the '%' sign to match zero or any number of characters, and with '_' sign to match a single character. It is commonly used in the WHERE clause of a SQL query to filter out the rows based on a specific pattern.