How to Select a Random Row from a SQL Database Table?

SQL random row query

Retrieving random rows from database tables occurs frequently in various applications. Although SQL does not provide a direct true random function, there are techniques to approximate it efficiently.

MySQL

To select random rows from a table in MySQL, use the following syntax:

<code class="language-sql">SELECT column
FROM table
ORDER BY RAND()
LIMIT 1</code>

PostgreSQL

Similar to MySQL, PostgreSQL also provides a convenient way to select random rows:

<code class="language-sql">SELECT column
FROM table
ORDER BY RANDOM()
LIMIT 1</code>

Microsoft SQL Server

In Microsoft SQL Server, you can use the NEWID() function to generate seemingly random values:

<code class="language-sql">SELECT TOP 1 column
FROM table
ORDER BY NEWID()</code>

IBM DB2

DB2 offers a slightly different approach to selecting random rows:

<code class="language-sql">SELECT column, RAND() AS IDX
FROM table
ORDER BY IDX
FETCH FIRST 1 ROWS ONLY</code>

Oracle

Oracle database systems have their own mechanisms to approximate randomness:

<code class="language-sql">SELECT column
FROM (
    SELECT column
    FROM table
    ORDER BY DBMS_RANDOM.VALUE
)
WHERE ROWNUM = 1</code>

By implementing these techniques, you can efficiently request random rows from a SQL database table without compromising data integrity. It is important to note that results may vary slightly from database engine to database engine, and the actual ordering of the data may affect the results.

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