How to update large table with millions of rows in SQL Server?

Question

I\'ve an UPDATE statement which can update more than million records. I want to update them in batches of 1000 or 10000. I tried with @@ROWCOUNT bu

Answer 1

Your print is messing things up, because it resets @@ROWCOUNT. Whenever you use @@ROWCOUNT, my advice is to always set it immediately to a variable. So:

DECLARE @RC int;
WHILE @RC > 0 or @RC IS NULL
    BEGIN
        SET rowcount 5;

        UPDATE TableName
            SET Value  = 'abc1'
            WHERE Parameter1  = 'abc' AND Parameter2  = 123 AND Value <> 'abc1';

        SET @RC = @@ROWCOUNT;
        PRINT(@@ROWCOUNT)
    END;

SET rowcount = 0;

And, another nice feature is that you don't need to repeat the update code.