i've something similar to 40K rows and that i must run update query such as this:

UPDATE table1 
 SET column1='very long value 1...', column2='normal lenght value 1a'
WHERE pid ='123' column3='ccc';

column1 is TEXT

column2 is Varchar(150)

...and i wish to use mysql query furthermore server resource friendly.

I wish to use something of that nature:

UPDATE table1 
   CASE pid
    WHEN '123' THEN 'very long value 1...' 
    WHEN '124' THEN 'very long value 2...'  
    WHEN '543' THEN 'very long value 4...'  
    WHEN pid='34532' THEN 'very long value 5...'
    ELSE column1 
   CASE pid
    WHEN '123' THEN 'normal lenght value 1a'
    WHEN '124' THEN 'normal lenght value 2a'
    WHEN '543' THEN 'normal lenght value 4a'
    WHEN pid='34532' THEN 'normal lenght value 5a'
    ELSE column2 
WHERE pid IN ('123','124','543', ...,'34532') AND column3='ccc';

and my real question is the number of rows i'm able to update in by doing this in a single query?

Can there be other server resource friendly approach to update this 40K rows?

Regards, Pit

i believe that it doesn't rely on the amount of rows however the query size !

how big one query its depend within the parameter



to improve this u look at :