How to use explain in SQL?

The EXPLAIN statement in SQL is used to explain the query execution plan. It can provide detailed information about how the query is executed, including the indexes used, join types, and execution order. The method to use the EXPLAIN statement is as follows: 1. Add the EXPLAIN keyword before the query statement. 2. Run the query statement with EXPLAIN. 3. View the returned execution plan information. The format and content of the execution plan information may vary depending on the database management system. Typically, the execution plan information will provide details such as the tables used, indexes, join types, scan types (such as full table scan or index scan), and execution order. This information can help developers optimize performance, understand query execution, and identify potential performance bottlenecks. For example, in MySQL, you can execute the EXPLAIN statement as follows:

EXPLAIN SELECT * FROM table_name WHERE column = 'value';

After execution, the EXPLAIN statement will return information about the query execution plan. It is important to note that the EXPLAIN statement only interprets the query execution plan and does not actually execute the query. Therefore, using the EXPLAIN statement will not have any impact on the data in the database.