FM ExecuteSQL returns different results than direct database query

Question

I am wondering if anyone can explain why I get different results for the same query string between using the ExecuteSQL function in FM versus querying the database through a database browser (I'm using DBVisualizer).

Specifically, if I run

SELECT COUNT(DISTINCT IMV_ItemID) FROM IMV

in DBVis, I get 2802. In FileMaker, if I evaluate the expression

ExecuteSQL ( "SELECT COUNT(DISTINCT IMV_ItemID) FROM IMV"; ""; "")

then I get 2898. This makes me distrust the ExecuteSQL function. Inside of FM, the IMV table is an ODBC shadow, connected to the central MSSQL database. In DBVis, the application connects via JDBC. However, I don't think that should make any difference.

Any ideas why I get a different count for each method?

Answer 1

Actually, it turns out that when FM executes the SQL, it factors in whitespace, whereas DBVisualizer (not sure about other database browser apps, but I would assume it's the same) do not. Also, since the TRIM() function isn't supported by MSSQL (from what I've seen, at least) it is necessary to make the query inside of the ExecuteSQL statement something like:

SELECT COUNT(DISTINCT(LTRIM(RTRIM(IMV_ItemID)))) FROM IMV

Weird, but it works!

Answer 2

FM keeps a cache of the shadow table's records (for internal field-id-mapping). I'm not sure if the ExecuteSQL() function causes a re-creation of the cache. In other words: maybe the ESS shadow table is out of sync. Try to delete the cache by closing and restarting the FM client or perform a native find first.

You can also try a re-connect to the database server via the Open File script step.

HTH