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		<title>row_number and partition by in Mysql</title>
		<link>https://www.dbrnd.com/2015/08/row_number-and-partition-by-in-mysql/</link>
					<comments>https://www.dbrnd.com/2015/08/row_number-and-partition-by-in-mysql/#comments</comments>
		
		<dc:creator><![CDATA[Anvesh Patel]]></dc:creator>
		<pubDate>Sat, 15 Aug 2015 06:56:53 +0000</pubDate>
				<category><![CDATA[MySQL]]></category>
		<category><![CDATA[Anvesh Patel]]></category>
		<category><![CDATA[database]]></category>
		<category><![CDATA[database research and development]]></category>
		<category><![CDATA[MySQL Command]]></category>
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		<category><![CDATA[ROW_NUMBER]]></category>
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					<description><![CDATA[Are row_number and partition by available in MySQL? Answer is NO. Microsoft SQL Server support row_number and partition by for finding the unique record from a set of duplicate records. We can also set the order of data. MySQL doesn&#8217;t provide this feature directly. We can achieve this by using an inline variable for SELECT [&#8230;]]]></description>
										<content:encoded><![CDATA[<p><a class="a2a_button_facebook" href="https://www.addtoany.com/add_to/facebook?linkurl=https%3A%2F%2Fwww.dbrnd.com%2F2015%2F08%2Frow_number-and-partition-by-in-mysql%2F&amp;linkname=row_number%20and%20partition%20by%20in%20Mysql" title="Facebook" rel="nofollow noopener" target="_blank"></a><a class="a2a_button_twitter" href="https://www.addtoany.com/add_to/twitter?linkurl=https%3A%2F%2Fwww.dbrnd.com%2F2015%2F08%2Frow_number-and-partition-by-in-mysql%2F&amp;linkname=row_number%20and%20partition%20by%20in%20Mysql" title="Twitter" rel="nofollow noopener" target="_blank"></a><a class="a2a_button_linkedin" href="https://www.addtoany.com/add_to/linkedin?linkurl=https%3A%2F%2Fwww.dbrnd.com%2F2015%2F08%2Frow_number-and-partition-by-in-mysql%2F&amp;linkname=row_number%20and%20partition%20by%20in%20Mysql" title="LinkedIn" rel="nofollow noopener" target="_blank"></a><a class="a2a_button_pinterest" href="https://www.addtoany.com/add_to/pinterest?linkurl=https%3A%2F%2Fwww.dbrnd.com%2F2015%2F08%2Frow_number-and-partition-by-in-mysql%2F&amp;linkname=row_number%20and%20partition%20by%20in%20Mysql" title="Pinterest" rel="nofollow noopener" target="_blank"></a><a class="a2a_button_reddit" href="https://www.addtoany.com/add_to/reddit?linkurl=https%3A%2F%2Fwww.dbrnd.com%2F2015%2F08%2Frow_number-and-partition-by-in-mysql%2F&amp;linkname=row_number%20and%20partition%20by%20in%20Mysql" title="Reddit" rel="nofollow noopener" target="_blank"></a><a class="a2a_button_pocket" href="https://www.addtoany.com/add_to/pocket?linkurl=https%3A%2F%2Fwww.dbrnd.com%2F2015%2F08%2Frow_number-and-partition-by-in-mysql%2F&amp;linkname=row_number%20and%20partition%20by%20in%20Mysql" title="Pocket" rel="nofollow noopener" target="_blank"></a><a class="a2a_dd addtoany_share_save addtoany_share" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.dbrnd.com%2F2015%2F08%2Frow_number-and-partition-by-in-mysql%2F&#038;title=row_number%20and%20partition%20by%20in%20Mysql" data-a2a-url="https://www.dbrnd.com/2015/08/row_number-and-partition-by-in-mysql/" data-a2a-title="row_number and partition by in Mysql"></a></p><p>Are row_number and partition by available in MySQL? </p>
<p><strong>Answer is NO.</strong></p>
<p>Microsoft SQL Server support row_number and partition by for finding the unique record from a set of duplicate records. We can also set the order of data. </p>
<blockquote><p>MySQL doesn&#8217;t provide this feature directly. We can achieve this by using an inline variable for SELECT statements.</p></blockquote>
<p><strong>Below is a full demonstration: </strong></p>
<p>I prepared a few scripts for sample data and stored procedure for finding the only unique records.</p>
<p><strong>Below is a full demonstration:</strong></p>
<pre class="crayon-plain-tag">/*Create sample database and table with sample data.*/
CREATE DATABASE `Employee`;

CREATE TABLE Employee.EmpDuplicate
(
	EmpRemarkID INTEGER
	,EmpID INTEGER
    ,EmpRemark VARCHAR(50)
);

INSERT INTO Employee.EmpDuplicate VALUES
(1,25,'abc'),(2,25,'abc'),(3,25,'abc')
,(4,26,'xyz'),(5,27,'pqr'),(6,27,'pqr')
,(7,27,'pqr'),(8,27,'pqr'),(9,28,'xvk')
,(10,28,'xvk'),(11,29,'pqr'),(12,29,'pqr')
,(13,29,'abc'),(14,30,'abc');</pre>
<pre class="crayon-plain-tag">/*Sample Stored Procedure to find Unique record from the group of duplicate.*/
DELIMITER $$
CREATE PROCEDURE Employee.usp_GETUniqueEmployeeRecords()
BEGIN

    SET @rn1:=1;
    SET @pk1:='';    				
    SELECT  
        EmpRemarkID
	,EmpID
	,EmpRemark				
    FROM
    (
	SELECT  
	   EmpRemarkID
	   ,EmpID
	   ,EmpRemark
	   ,@rn1 := IF(@pk1=CONCAT(EmpID,EmpRemark), @rn1+1,1) AS rowNumber
	   ,@pk1 := CONCAT(EmpID,EmpRemark)         
	FROM
	(
	    SELECT  
         	EmpRemarkID
		,EmpID
		,EmpRemark
	    FROM Employee.EmpDuplicate
	) A
    ) B WHERE rowNumber=1;			
END$$
DELIMITER ;</pre>
<pre class="crayon-plain-tag">/*Execute this Stored Procedure.*/
CALL Employee.usp_GETUniqueEmployeeRecords()</pre>
<p><strong>Results:</strong></p>
<p><a href="https://www.dbrnd.com/wp-content/uploads/2015/08/MySQLUniuqeRecords.png"><img fetchpriority="high" decoding="async" class="alignnone wp-image-391 size-full" title="MySQL Uniuqe Records" src="https://www.dbrnd.com/wp-content/uploads/2015/08/MySQLUniuqeRecords.png" alt="MySQLUniuqeRecords" width="297" height="229" srcset="https://www.dbrnd.com/wp-content/uploads/2015/08/MySQLUniuqeRecords.png 297w, https://www.dbrnd.com/wp-content/uploads/2015/08/MySQLUniuqeRecords-150x116.png 150w" sizes="(max-width: 297px) 100vw, 297px" /></a></p>
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