I have two tables, one of which contains a Key (PathwayNumber) that I need to remove based on its existence in the other. the data against each key is different albeit that the Key is the same.
I have tried a couple of variations but most recently the script looks like below. Without the Not Exists I have just over 5000 records in table1 and a couple of million in table 2. With the statement, table 2 is empty.