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Pattern matching with LIKE

Search text with LIKE and the %, _ wildcards.

Pattern matching with LIKE

LIKE searches for a pattern in text. Two wildcards are used: % matches zero or more characters, _ matches exactly one character.

SELECT name FROM customers
WHERE name LIKE 'A%';

This returns all names starting with A. %a% finds names containing a.

name is selected from customers. WHERE keeps only the rows where name LIKE 'A%' holds.

Pattern matching with LIKE — details

The position of wildcards changes the meaning: 'A%' starts with A, '%a' ends with a, '%a%' contains a. Case sensitivity depends on the database.

Use _ for exactly one character: LIKE '_a%' finds values whose second letter is a.

Practice Pattern matching with LIKE

Select name from customers whose name contains the letter 'a'.

Starter code

query.sql
-- write a LIKE pattern
SELECT name
FROM customers
WHERE

Sample solution

query.sql
SELECT name
FROM customers
WHERE name LIKE '%a%'

Expected output

name
Ayşe
Alex
Ahmet

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 Starts with A

Question 
SELECT name FROM customers
WHERE name LIKE ____;
Answer 
SELECT name FROM customers
WHERE name LIKE 'A%';

Explanation: LIKE 'A%' finds text that starts with A; % means any number of characters after it.

2 Pattern matching with LIKE: match the terms

Term Meaning
'A%' starts with A
'%a' ends with a
'%a%' contains a
'A_' A plus one letter

3 What does % match?

  • A space
  • Exactly one character
  • Zero or more characters Correct answer
  • A number

Explanation: % matches zero or more characters.

All lessons in Beginner

1 SELECT basics

  1. What is SELECT?
  2. Selecting all columns
  3. Selecting specific columns
  4. Column aliases with AS
  5. Literal values
  6. Summary - SELECT basics

2 WHERE filtering

  1. What is WHERE?
  2. Comparison operators
  3. AND and OR
  4. IN and BETWEEN
  5. Pattern matching with LIKE
  6. Summary - WHERE filtering

3 Ordering and limit

  1. ORDER BY
  2. ASC and DESC
  3. Multi-column ordering
  4. LIMIT
  5. OFFSET
  6. Summary - Ordering and limit

4 Project: CRUD app

  1. Project design
  2. Reading data
  3. Inserting data
  4. Updating data
  5. Deleting data

5 Data types

  1. Integer types
  2. Decimal types
  3. CHAR and VARCHAR
  4. DATE and TIME
  5. BOOLEAN
  6. Summary - Data types

6 Operators

  1. Arithmetic operators
  2. Comparison operators
  3. Logical operators
  4. IS NULL
  5. String concatenation
  6. Summary - Operators

7 String functions

  1. UPPER and LOWER
  2. LENGTH
  3. SUBSTRING
  4. TRIM
  5. CONCAT
  6. Summary - String functions

8 Project: Shopping cart

  1. Cart design
  2. Listing products
  3. Adding to cart
  4. Calculating total
  5. Removing from cart

9 Number functions

  1. ROUND
  2. CEIL and FLOOR
  3. ABS
  4. POWER and SQRT
  5. MOD
  6. Summary - Number functions

10 Date functions

  1. CURRENT_DATE and NOW
  2. EXTRACT
  3. Date arithmetic
  4. DATEDIFF
  5. Date formatting
  6. Summary - Date functions

11 NULL handling

  1. What is NULL?
  2. IS NULL
  3. COALESCE
  4. NULLIF
  5. Three-valued logic
  6. Summary - NULL handling

12 DISTINCT

  1. What is DISTINCT?
  2. DISTINCT on one column
  3. Multi-column DISTINCT
  4. DISTINCT with aggregates
  5. DISTINCT vs GROUP BY
  6. Summary - DISTINCT

13 INSERT

  1. INSERT basics
  2. Inserting into specific columns
  3. Multiple rows
  4. INSERT with SELECT
  5. DEFAULT values
  6. Summary - INSERT

14 UPDATE

  1. UPDATE basics
  2. Conditional UPDATE
  3. Multi-column UPDATE
  4. Calculated updates
  5. UPDATE pitfalls
  6. Summary - UPDATE

15 DELETE

  1. DELETE basics
  2. Conditional DELETE
  3. DELETE vs TRUNCATE
  4. Emptying a table
  5. Safe deletion
  6. Summary - DELETE

16 CREATE TABLE

  1. CREATE TABLE basics
  2. Column definitions
  3. NOT NULL
  4. DEFAULT
  5. PRIMARY KEY
  6. Summary - CREATE TABLE

17 Constraints

  1. UNIQUE constraint
  2. CHECK constraint
  3. FOREIGN KEY
  4. CASCADE
  5. Constraint management
  6. Summary - Constraints

18 Simple JOIN

  1. What is JOIN?
  2. INNER JOIN
  3. The ON clause
  4. Table aliases
  5. Multi-table JOIN
  6. Summary - Simple JOIN

19 Project: Inventory system

  1. Inventory design
  2. Product table
  3. Stock movements
  4. Stock report
  5. Low stock alert

20 Beginner final

  1. Customer query
  2. Order report
  3. Data update
  4. Table redesign