# **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:

```sql
-- 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**

```text
> 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 `seed` parameter is not specified, the current time is the seed value by default. The return value type is consistent with the input type. <br> MatrixOne does not support the specified seed value. |

## **Example**

- Example 1

```text
mysql> SELECT RAND();
+--------------------------+
| rand() |
+--------------------------+
| 0.25193285156620004 |
+--------------------------+
1 row in set (0.00 sec)
```

- Example 2

```text
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).