MySQL: Explain Limit and OFFSET in MySQL.

 

In MySQL, the LIMIT and OFFSET clauses are used in conjunction with the SELECT statement to control the number of rows returned by a query and to skip a certain number of rows, respectively. These clauses are often used for pagination or to retrieve a subset of rows from a larger result set.

Here's an explanation of both:

1. LIMIT: The LIMIT clause is used to restrict the number of rows returned by a query. It specifies the maximum number of rows to return.

   Syntax:

   sql
   SELECT columns
   FROM table
   LIMIT row_count;
   

   Example:

   sql
   SELECT * FROM products
   LIMIT 10;
   

   This query will return the first 10 rows from the products table.

2. OFFSET: The OFFSET clause is used to skip a certain number of rows before starting to return the rows. It is often used in combination with LIMIT to implement pagination.

   Syntax:

   sql
   SELECT columns
   FROM table
   LIMIT row_count OFFSET offset_value;
   

   Example:

   sql
   SELECT * FROM products
   LIMIT 10 OFFSET 20;
   

   This query will return 10 rows from the products table, starting from the 21st row (skipping the first 20 rows).

When using LIMIT and OFFSET, it's important to note that:

• The LIMIT and OFFSET clauses should appear at the end of the SELECT statement, after the FROM, WHERE, GROUP BY, HAVING, and ORDER BY clauses.

• The row_count in the LIMIT clause specifies the maximum number of rows to return, and offset_value in the OFFSET clause specifies the number of rows to skip.

• The ordering of rows can be controlled using the ORDER BY clause before applying LIMIT and OFFSET to ensure consistent results.

Example with ORDER BY, LIMIT, and OFFSET:

sql
SELECT *
FROM orders
ORDER BY order_date DESC
LIMIT 10 OFFSET 20;

This query will return 10 rows from the orders table, starting from the 21st row, ordered by order_date in descending order.