Client DataSets and Mem requirements ...

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5 total messages Started by Nick Rambarransingh Sun, 30 Jul 2000 00:00

#983

Author: Nick Rambarransingh
Date: Sun, 30 Jul 2000 00:00

24 lines
1691 bytes

Good Day All,

  I am of the impression that once you design the client dataset to
server dataprovider, one should not be changing the SQL query commands.
I understand this isn't true because of the CommandText property.

  However, everytime I converse with someone, there seems to be the
usual question, why would I want to change the SQL statement.  It has
got me wondering, am I doing something wrong?  For example, in order to
login, I created a form that collects userid and password.  From this I
dynamically change the SQL to get that persons statistics, lastlogin,
loginstatus, etc.  There is nothing wrong with this - right ?

  Last but not least, I am having trouble talking to the datamodule,
which is in a client application, but my loginf form, and others, will
all be in individual packages.  Can I not access the data module from
the client app?  In the IDE, when I press "ClientModule->", I get the
list of objects.  However, at compile time, the linker does not know
about the ClientModule anymore.  I don't know why, or what to do.

  Someone please point me in the right direction.

Thanks, Nick
Borland Forever ...

Re: Client DataSets and Mem requirements ...

#988

Author: Mark Cashman (TeamB)
Date: Tue, 01 Aug 2000 00:00

12 lines
1051 bytes

Hi, Nick!

In many situations you can use TParam settings to influence what the
query goes after without changing the SQL. However, are you having
specific problems when you change the SQL at run time?

------
Mark Cashman, TeamB C++ Builder
http://www.temporaldoorway.com/programming/index.htm
C++ Builder, JBuilder programming information
Home of The C++ Builder Programmer's Webring - Join us!
------

Re: Client DataSets and Mem requirements ...

#989

Author: Nick Rambarransingh
Date: Tue, 01 Aug 2000 00:00

27 lines
1890 bytes

Hi Mark Cashman (TeamB),

"In many situations you can use TParam settings to influence what the
query goes after without changing the SQL."
- Do you mean I can select * from my query on the server,  and then from
the client, if I pass a particular param, this will automatically filter
the records being sent to me by the provider ?
"However, are you having specific problems when you change the SQL at
run time?"
- Most definitely.  I don't get the answer I am looking for.  I have my
query set to select all.  Then, in the formActivate method, I attempt to
Activate the dataset.  I have the user enter UserId and Password.  I
then set the command text to select the record where the userid equals
"Whatever".  I then test the result to determine what I shouuld tell the
user: you must change your pw, invalid id or pw, etc., etc.

  And here is something else strange - If I active the dataset, do
something with it, and then close the dataset, the minute I try to
activate is again, I get an OleEnterprise error - unable to get cursor
handle, or something to that effect.  This always happens following the
DataSet->Active = TRUE.

  I am not sure where to go from here, but I tell you, I getting
frustrated ....

Thanks, Nick
Borland Forever ...

Re: Client DataSets and Mem requirements ...

#990

Author: Mark Cashman (TeamB)
Date: Wed, 02 Aug 2000 00:00

20 lines
1267 bytes

Hi, Nick!

Set up your query as

    SELECT * FROM Login WHERE UserID=:UserID AND
SomethingElse=:SomethingElse

Then set the Query1->Params->ParamByName('UserID')->AsString = Whatever,
etc.
Then open the query. It will select for the values you specified.

Does that help? There's a section in the Developer's Guide on this,
also, IIRC.

------
Mark Cashman, TeamB C++ Builder
http://www.temporaldoorway.com/programming/index.htm
C++ Builder, JBuilder programming information
Home of The C++ Builder Programmer's Webring - Join us!
------

Re: Client DataSets and Mem requirements ...

#998

Author: Nick Rambarransingh
Date: Fri, 11 Aug 2000 00:00

32 lines
1612 bytes

Marck,

  Actually it did help.  I continued to plug away at it and eventuall got
it.  However, I have discovered the Param thing on the server, and setting
the values on the clinet and sending them to the server.  Very cool !

Thanks, Nick


Mark Cashman (TeamB) wrote:

> Hi, Nick!
>
> Set up your query as
>
>     SELECT * FROM Login WHERE UserID=:UserID AND
> SomethingElse=:SomethingElse
>
> Then set the Query1->Params->ParamByName('UserID')->AsString = Whatever,
> etc.
>
> Then open the query. It will select for the values you specified.
>
> Does that help? There's a section in the Developer's Guide on this,
> also, IIRC.
>
> ------
> Mark Cashman, TeamB C++ Builder
> http://www.temporaldoorway.com/programming/index.htm
> C++ Builder, JBuilder programming information
> Home of The C++ Builder Programmer's Webring - Join us!
> ------

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