Pattern Matching

Imagine we need to find all products that have a certain word in their name from the online store’s database. For instance, we might want to identify all products whose names contain “book” so that we can run a promotional discount on them. Searching by exact matches might not be enough if we need to handle variations in spelling, partial terms, or different letter cases. This is where pattern matching becomes valuable.

Pattern matching in SQL is a powerful tool that allows us to find specific data within a table that follows a defined pattern. This is particularly useful when searching for records with similar attributes, such as names starting with a certain letter or products containing specific keywords.

Pattern matching allows us to retrieve rows that match partial strings instead of requiring exact matches. This is important whenever we deal with data that might not follow a strict or uniform naming convention.

Let's explore the concept of pattern matching in SQL. We'll go step by step to:

• Understand the purpose and importance of pattern matching in SQL.

• Learn how to perform pattern matching with the LIKE operator.

• Learn how to use wildcards for pattern matching.

Using the LIKE operator

When working with user-generated content or when product names and descriptions do not follow a strict pattern, we cannot rely solely on equality operators. If we suspect a customer’s search term is contained somewhere in a product name, LIKE helps us find it without knowing the exact string up front.

In SQL, the LIKE operator is used to search for a specified string pattern in a column. The syntax of the LIKE operator is shown below: