Comparing dates as conditions for inserting rows in table

[fredo97]

Hi,

I'm new to Access/SQL and have a problem with a query that I just cant seem to be able to solve.

So, I have an Access database containing client number, security name and date, that information has to be updated every month, the source for the update being an excel file that I link to the Access database. But I dont want to overwrite on the existing data so what i wanted to do was add the current month's data, when it's not already in there.

What I did was an insert query which inserts the data from the excel file to the table in the Access database only if the column containing the date of the data is different from what is already in the database.

Here is what I came up with and it is not workin and i dont understand why:

INSERT INTO DatabaseTable ( Client, Security, Date )
SELECT ExcelTable.Client, ExcelTable.[Security Description], ExcelTable.Date
FROM ExcelTable
WHERE (((Exists (SELECT 1 FROM DatabaseTable WHERE DatabaseTable.Date = ExcelTable.Date)=false)));

The query doesnt insert any rows and looks as though it considers the dates from the two tables are identical even though they are not.

Can anyone help please ?

Thanks,

Fred

 

[wilpeter]

It looks as though the SELECT and FROM rows in your SQL should precede the EXISTS row. But check out this site: http://www.techonthenet.com/sql/exists.php to make sure you follow the syntax.

 

[vbaInet]

Also the Insert statement is wrong syntax.

 

[fredo97]

Hi
Thanks for the input, I actually solved the problem by using a Left Join .
Rgds
Fred

 

[vbaInet]

Glad to know you sorted it out.