SQLQuery.RecordCount messes up.

[Nordlund]

Hi.
Im trying to implement dbExpress on our application
(Se earlier threads about environment variables and so on).

Has anyone kicked out BDE and replaced it with dbExpress?

dbExpress seems to have a bunch of restrictions like RecordCount. You can't use RecordCount if you have:

SELECT DISTINCT

or if you are using a question like this:

SELECT * FROM Table T WHERE T.Field = 'Test'

(I know, the T is unnessecary in this case, but it was an example.).

//Nordlund

 

[hilfy]

RecordCount has never reliably worked for the BDE TQuery, so I'm not surprised it doesn't work in the DataExpress components. The best way to get the record count is in a separate query:

Select count(*)
From table T
where t.field := 'Test'

-Dell

 

[Nordlund]

Yep. I saw that.
And when I dug more into the dbExpress sourcecode, I saw a few more restrictions.

I solved it by creating a descendant of TSQLQuery and overload the Recordcount property with a "while not EOF"-counter.



//Nordlund

 

[hilfy]

The problem with a "while not EOF" counter comes when you have a large dataset - it can take some time to do the count. If you're only working with small datasets (couple hundred records as opposed to thousands) it won't be that much of an issue, though.

-Dell

 

[Nordlund]

Hi.
Yep, It's mainly small datasets. I first try to use the original RecordCount, and if it throws an error, I loop throut the dataset...



//Nordlund