Hi,

I have two tables in the database. The two tables are same schema. One act as source and other as destination. I have to find the difference between two tables. The difference is the records present in the source and not in destination. The table has composite key. I have used INNER JOIN, as shown below

SELECT DISTINCT source.locations, source.station, source.unit_details,
FROM production.step_instances source
INNER JOIN test.step_instances destination ON ( destination.locations!= source.locations AND destination.station != source.station AND destination.unit_details!= source.unit_details);

The columns locations, station and unit_details are composite keys with different data types. But I found, some issues with the data in the table from the above query. Is this possible to use some mysql function for composite key or other query to find the difference?

Thanks

how about:
SELECT DISTINCT source.locations, source.station, source.unit_details,
FROM production.step_instances source
WHERE NOT EXISTS (select 1 from test.step_instances destination
WHERE destination.locations = source.locations AND destination.station = source.station AND destination.unit_details = source.unit_details)


Dave Nance

Check this one out : Microshell Comparing data from 2 database tables