Random function notes in MySQL

1, Test table structure:
mysql> desc Test_user;
+---------+-------------+------+-----+---------+----------------+
        | Field   | Type        | Null | Key | Default | Extra          |
        +---------+-------------+------+-----+---------+----------------+
        | ID      | int     | NO   | PRI | NULL    | auto_increment |
        | Name    | varchar (50) | NO   |     | NULL    |                |
        | Age     | int (one)     | YES  |     | NULL    |                |
        | Address | varchar (50) | YES  |     | NULL    |                |

2. Add random fields and indexes:
Mysql> ALTER TABLE Test_user add random double;
Mysql> ALTER TABLE Test_user Add index (random)

3. Fill in the Random field data:
mysql> Update test_user Set random = rand ();

4, randomly returns a piece of data:

Mysql> Select ID, name from Test_user where the Random > rand () Order by random LimiT 1;

+----+------+
| ID | name |
+----+------+
| 9 | com |
+----+------+
1 row in Set (0.00 sec)

Mysql> Select ID, name from Test_user where the Random > rand () Order by random Limi
T 1;
+----+------+
| ID | name |
+----+------+
| 7 | www |
+----+------+
1 row in Set (0.00 sec)

Random function notes in MySQL