T-SQL UPDATE statement affects more records than select statement
问题 The following is driving me nuts, please help me! As a check before running an UPDATE statement (T-SQL; SQL Server 2012) I run: select * from Treatment_Day42 where td42pinit = 'J M' and td42pid = 'ADA'; and I get 1 row returned, as I expect. However, running update Treatment_Day42 set td42pid = 'ADA252' where td42pinit = 'J M' and td42pid = 'ADA'; affects four records, not one as in the select statement with the exact same WHERE clause. I get the row returned by the select plus 3 other rows