I have managed to set up a linked server to a MySQL database and i want to update the MySQL database using a table within SQL Server. I tried the below code:
UPDATE OPENQUERY(DQ_TESTDATA,'select webmaster_id, dupe_master_id, dupe_flag from webmaster')
SET dupe_master_id = r.MID,
dupe_flag = 'M'
FROM (Select * from dbo.DQResults) as r INNER JOIN
OPENQUERY(DQ_TESTDATA,'select webmaster_id from webmaster') AS w
ON r.MID = w.webmaster_id
but it updated every record in the database (just over 2 million).
it should only be updating around 662510.
Can anyone see why this is happening and what the SQL update query should be?