MySQL LIMIT

Summary: in this tutorial, you will learn how to use the MySQL LIMIT clause to constrain the number of rows returned by a query.

Introduction to MySQL LIMIT clause

The LIMIT clause is used in the SELECT statement to constrain the number of rows to return. The LIMIT clause accepts one or two arguments. The values of both arguments must be zero or positive integers.

The following illustrates the LIMIT clause syntax with two arguments:

SELECT 
    select_list
FROM
    table_name
LIMIT [offset,] row_count;Code language: SQL (Structured Query Language) (sql)

In this syntax:

• The offset specifies the offset of the first row to return. The offset of the first row is 0, not 1.
• The row_count specifies the maximum number of rows to return.

The following picture illustrates the LIMIT clause:

When you use the LIMIT clause with one argument, MySQL will use this argument to determine the maximum number of rows to return from the first row of the result set.

Therefore, these two clauses are equivalent:

LIMIT row_count;Code language: SQL (Structured Query Language) (sql)

And

LIMIT 0 , row_count;

In addition to the above syntax, MySQL provides the following alternative LIMIT clause syntax:

LIMIT row_count OFFSET offsetCode language: SQL (Structured Query Language) (sql)

The LIMIT and ORDER BY clauses

By default, the SELECT statement returns rows in an unspecified order. When you add the LIMIT clause to the SELECT statement, the returned rows are unpredictable.

Therefore, to ensure the LIMIT clause returns an expected output, you should always use it with an ORDER BY clause like this:

SELECT 
    select_list
FROM 
    table_name
ORDER BY 
    sort_expression
LIMIT offset, row_count;Code language: SQL (Structured Query Language) (sql)

The following picture illustrates the evaluation order of the LIMIT clause in the SELECT statement:

MySQL LIMIT clause examples

We’ll use the customers table from the sample database for demonstration.

1) Using MySQL LIMIT to get the highest or lowest rows

This statement uses the LIMIT clause to get the top five customers who have the highest credit:

SELECT 
    customerNumber, 
    customerName, 
    creditLimit
FROM
    customers
ORDER BY creditLimit DESC
LIMIT 5;Code language: SQL (Structured Query Language) (sql)

Try It Out

In this example:

• First, the ORDER BY clause sorts the customers by credits from high to low.
• Then, the LIMIT clause returns the first 5 rows.

Similarly, this example uses the LIMIT clause to find five customers who have the lowest credits:

SELECT 
    customerNumber, 
    customerName, 
    creditLimit
FROM
    customers
ORDER BY creditLimit
LIMIT 5;Code language: SQL (Structured Query Language) (sql)

Try It Out

In this example:

• First, the ORDER BY clause sorts the customers by credits from low to high.
• Then, the LIMIT clause returns the first 5 rows.

Because there are more than 5 customers that have credits zero, the result of the query above may lead to an inconsistent result.

To fix this issue, you need to add more columns to the ORDER BY clause to constrain the row in unique order:

SELECT 
    customerNumber, 
    customerName, 
    creditLimit
FROM
    customers
ORDER BY 
    creditLimit, 
    customerNumber
LIMIT 5;Code language: SQL (Structured Query Language) (sql)

Try It Out

2) Using MySQL LIMIT clause for pagination

When you display data on the screen, you often want to divide rows into pages, where each page contains a limited number of rows like 10 or 20.

To calculate the number of pages, you take the total rows divided by the number of rows per page. For fetching rows of a specific page, you can use the LIMIT clause.

This query uses the COUNT(*) aggregate function to get the total rows from the customers table:

SELECT 
    COUNT(*) 
FROM 
    customers;Code language: SQL (Structured Query Language) (sql)

+----------+
| COUNT(*) |
+----------+
|      122 |
+----------+
1 row in set (0.00 sec)Code language: JavaScript (javascript)

Suppose that each page has 10 rows; to display 122 customers, you have 13 pages. The last 13th page contains two rows only.

This query uses the LIMIT clause to get rows of page 1 which contains the first 10 customers sorted by the customer name:

SELECT 
    customerNumber, 
    customerName
FROM
    customers
ORDER BY customerName    
LIMIT 10;Code language: SQL (Structured Query Language) (sql)

Try It Out

This query uses the LIMIT clause to get the rows of the second page that include rows 11 – 20:

SELECT 
    customerNumber, 
    customerName
FROM
    customers
ORDER BY customerName    
LIMIT 10, 10;Code language: SQL (Structured Query Language) (sql)

Try It Out

In this example, the clause LIMIT 10, 10 returns 10 rows for the rows 11 – 20.

3) Using MySQL LIMIT to get the n^th highest or lowest value

To get the n^th highest or lowest value, you use the following LIMIT clause:

SELECT select_list
FROM table_name
ORDER BY sort_expression
LIMIT n-1, 1;Code language: SQL (Structured Query Language) (sql)

The clause LIMIT n-1, 1 returns 1 row starting at the row n.

For example, the following finds the customer who has the second-highest credit:

SELECT 
    customerName, 
    creditLimit
FROM
    customers
ORDER BY 
    creditLimit DESC    
LIMIT 1,1;Code language: SQL (Structured Query Language) (sql)

Try It Out

Let’s double-check the result. This query returns all customers sorted by credits from high to low:

SELECT 
    customerName, 
    creditLimit
FROM
    customers
ORDER BY 
    creditLimit DESC;Code language: SQL (Structured Query Language) (sql)

Try It Out

As you can see clearly from the output, the result was correct as expected.

Note that this technique works when there are no two customers who have the same credit limits. To get a more accurate result, you should use the DENSE_RANK() window function.

MySQL LIMIT & DISTINCT clauses

If you use the LIMIT clause with the DISTINCT clause, MySQL immediately stops searching when it finds the number of unique rows specified in the LIMIT clause.

The example uses the LIMIT clause with the DISTINCT clause to return the first five unique states in the customers table:

SELECT DISTINCT
    state
FROM
    customers
WHERE
    state IS NOT NULL
LIMIT 5;Code language: SQL (Structured Query Language) (sql)

Try It Out

Summary

• Use the MySQL LIMIT clause to constrain the number of rows returned by the SELECT statement.