select update in mysql

First of all you fetch total information in one DataSet (or) DataTable.
After that you can use foreach loop , fetch the each and every row information. Inside the foreach you write you update query. this is in application wise...

ex:

DataTable dt=//total data;

foreach(DataRow dr in dt.Rows)
{
    //your update query
}

In DB itself also you can do this

Ex:

DataSet ds= //data;
string data =ds.GetXML();

In your SQL SP itself you can follow the below steps to achieve this
Fetch the XML path information and store it in one temprory table. Then,

DECLARE @MINCOUNT INT , @MAXCOUNT INT        
SELECT @MAXCOUNT = COUNT(*) FROM #TEMPTable        
SET @MINCOUNT = 1    

  
DECLARE @Update_Count VARCHAR(10)  
SET @Update_Count=0   

While( @MINCOUNT<= @MAXCOUNT) 
BEGIN
   //UPDATE QUERY
   //SET @Update_Count=@Update_Count+1
SET  @MINCOUNT= @MINCOUNT+1
END

THIS is DB side....