You’re going to delve into an essential yet often overlooked operator in the SQL toolkit – the ‘LIKE’ operator
What Is the SQL ‘LIKE’ Operator?
The ‘LIKE’ operator in SQL is a logical operator that you can use in the WHERE clause to search for specific patterns in a column. This operator becomes particularly useful when you’re searching for partial information in the database fields, and you don’t know the exact data.
So, let’s break down the ‘LIKE’ operator, including its usage, examples, and useful tips. I will make sure this is understandable, even for beginners.
Syntax of SQL ‘LIKE’
The basic syntax for ‘LIKE’ is
SELECT column1, column2, ...
FROM table_name
WHERE columnN LIKE pattern;
Here, ‘pattern’ can be a combination of ordinary characters and wildcard characters.
Wildcards in SQL
To fully utilize the ‘LIKE’ operator, it’s crucial to understand wildcards. These are special characters that help you match other characters in a string. There are two common wildcards used with ‘LIKE’:
1) %: Represents zero, one, or multiple characters
2) _: Represents a single character
Let’s Explore Some SQL ‘LIKE’ Examples
Imagine you have a table named Books with the following data
| BookID | Title |
|--------|---------------------------|
| 1 | Learning SQL Basics |
| 2 | Mastering SQL |
| 3 | Python for Beginners |
| 4 | Advanced SQL Techniques |
| 5 | Introduction to Databases |
1) Find All Books With “SQL” in the Title
To find all the books containing “SQL” in their titles, you can use the ‘%’ wildcard on both sides of “SQL”. Here’s the SQL statement:
SELECT *
FROM Books
WHERE Title LIKE '%SQL%';
Running this command returns all books with “SQL” anywhere in their title
| BookID | Title |
|--------|---------------------------|
| 1 | Learning SQL Basics |
| 2 | Mastering SQL |
| 4 | Advanced SQL Techniques |
2) Find All Books Starting With “Advanced”
To find all books starting with “Advanced”, place the ‘%’ wildcard after “Advanced”. Here’s the SQL statement
SELECT *
FROM Books
WHERE Title LIKE 'Advanced%';
Running this command returns any book with a title starting with “Advanced”
| BookID | Title |
|--------|---------------------------|
| 4 | Advanced SQL Techniques |
3) Find All Books Ending With “Basics”
To find books whose title ends with “Basics”, place the ‘%’ wildcard before “Basics”. Here’s the SQL statement
SELECT *
FROM Books
WHERE Title LIKE '%Basics';
Running this command returns any book with a title ending with “Basics”
| BookID | Title |
|--------|---------------------------|
| 1 | Learning SQL Basics |
An Important Note: SQL ‘LIKE’ is Case-Insensitive
Remember, SQL is case-insensitive. This means that ‘LIKE’ ‘A%’ and ‘LIKE’ ‘a%’ will return the same results.
Wrapping Up
The ‘LIKE’ operator, though simple, can be incredibly powerful when combined with wildcards. It’s a key tool in your SQL kit, enabling you to perform pattern matching and partial searches in your database.
The secret to mastering SQL, as with any other skill, is practice. So, start experimenting with ‘LIKE’ and see what you can discover!
