Duplicated Data

[jamesjohnturner]

I have a table where csv files get imported to on a daily basis. The key fields I am working with are a supply number and date. The problem I have is that sometimes the csv file will contain information that is correcting/updating information held in the table. This is creating duplicated records.

I need to either create a query to find records that have the same supply number and date or find a way of overwriting the records in the table with the new data.

I hope I have explained myself clearly, but any suggestions will be much appreciated.

 

[plog]

You would need to bring your new data into a temporary table (TMP) and not directly into the main table (MAIN). Then to move your data in the appropriate manner you would need 2 queries:

1. Would use an INNER JOIN between TMP and MAIN. This query will provide the records that need to be updated.

2. Would use a LEFT JOIN from TMP to MAIN and would exclude any non null values in MAIN. This query will provide the records that need to be added.

 

[jamesjohnturner]

So will the LEFT JOIN overwrite old data that has the same date?