RAND()¶
Function Description¶
The RAND() function is used to generate a random number of type Float64 between 0 and 1. It accepts no parameters and each call produces an unpredictable and non-repetitive random number.
If you need to randomly select data from the table, you can use the RAND() function to generate a random number. You can sort the data in the table using ORDER BY according to this random number. For example:
-- Get all data randomly from the table and sort it in random order. The order of each query result may be different.
SELECT * FROM table ORDER BY RAND();
Function Syntax¶
> RAND([seed])
Parameter definition¶
Parameters |
Description |
|---|---|
seed |
Optional parameters. Is an integer value that specifies the seed value when generating a random number. If the |
Example¶
Example 1
mysql> SELECT RAND();
+--------------------------+
| rand() |
+--------------------------+
| 0.25193285156620004 |
+--------------------------+
1 row in set (0.00 sec)
Example 2
CREATE TABLE Users (
ID INT PRIMARY KEY AUTO_INCREMENT,
UserName VARCHAR(255) NOT NULL,
Email VARCHAR(255));
INSERT INTO Users (UserName, Email) VALUES
('John', 'john@example.com'),
('Jane', 'jane@example.com'),
('Alice', 'alice@example.com'),
('Bob', 'bob@example.com');
-- Randomly select a user's information from the Users table
mysql> SELECT * FROM Users ORDER BY RAND() LIMIT 1;
+------+--------------------------------------------+
| id | username | email |
+------+--------------------------------------------+
| 4 | Bob | bob@example.com | -- Bob's information is randomly selected
+------+--------------------------------------------+
1 row in set (0.01 sec)
-- Execute the above query again, and the selected user may be another user
mysql> SELECT * FROM Users ORDER BY RAND() LIMIT 1;
+------+-----------------------------------------------------------------------------------------------------------------------
| id | username | email |
+------+-----------------------------------------------------------------------------------------------------------------------
| 3 | Alice | alice@example.com | -- Alice's information is randomly selected
+------+-----------------------------------------------------------------------------------------------------------------------
1 row in set (0.01 sec)
limit¶
MatrixOne does not currently support specifying the seed value of the RAND(seed) function (i.e. the seed parameter).