MySQL database optimization (ii) Comparison of the run speed of is NULL, ISNULL (), and Ifnull () in MySQL

In the query process, we often use non-null and is NULL queries, in order to more efficient query, we should know that method faster.

In the previous article, we have added some data. Based on this data, we can do some validation.

The first step, is null compared to ISNULL ()

SELECT * from table name where field name is NULL

SELECT * FROM table name where ISNULL (field name)

As can be seen above, is null than ISNULL () a little faster.

The second step, the comparison of IS null and ifnull ()

SELECT * from table name where field name is NULL

SELECT * FROM table name where Ifnull (field name, ' 0 ') = ' 0 ';

As can be seen from the above, it can be seen that ifnull () is a little faster than is null.

In summary, the query null value runs basically ifnull () >is null>isnull ().

MySQL database optimization (ii) Comparison of the run speed of is NULL, ISNULL (), and Ifnull () in MySQL