MaxValue

[Guest]

Hi,

How can I pls get the maxvalue and the minvalue in a specific colunm in a
dataset or datareader.


thanks

 

[Carlos J. Quintero [VB MVP]]

If you don´t use a query with the MIN(...) and MAX(...) statements to make
the database do the calculation for you, you need to traverse the recordset
yourself to get the min and max values, or sort it by that column and get
the first and last row...

--

Best regards,

Carlos J. Quintero

MZ-Tools: Productivity add-ins for Visual Studio .NET, VB6, VB5 and VBA
You can code, design and document much faster.
Free resources for add-in developers:
http://www.mztools.com

 

[Guest]

and how to get the first and last record using the dataset facilities
--
Regads,
Rochdi

If you don´t use a query with the MIN(...) and MAX(...) statements to make
the database do the calculation for you, you need to traverse the recordset
yourself to get the min and max values, or sort it by that column and get
the first and last row...

--

Best regards,

Carlos J. Quintero

MZ-Tools: Productivity add-ins for Visual Studio .NET, VB6, VB5 and VBA
You can code, design and document much faster.
Free resources for add-in developers:
http://www.mztools.com

 

[Tom Shelton]

Hi,

How can I pls get the maxvalue and the minvalue in a specific colunm in a
dataset or datareader.


thanks

Not sure about the datareader, but you can select datarows via critera
on a datatable using the Select method.

 

[Guest]

Sorry but I meant from the dataset or reader not from a table in the
database!!!!
--
Regads,
Rochdi

SELECT MAX(Field)
FROM TableName


-----Original Message-----
From: Tom Shelton [mailto:[email protected]]
Posted At: Tuesday, September 20, 2005 12:27 PM
Posted To: microsoft.public.dotnet.languages.vb
Conversation: MaxValue
Subject: Re: MaxValue

Hi,

How can I pls get the maxvalue and the minvalue in a specific colunm in a
dataset or datareader.


thanks

Not sure about the datareader, but you can select datarows via critera
on a datatable using the Select method.

 

[Marcelo]

SELECT MAX(Field)
FROM TableName


-----Original Message-----
From: Tom Shelton [mailto:[email protected]]
Posted At: Tuesday, September 20, 2005 12:27 PM
Posted To: microsoft.public.dotnet.languages.vb
Conversation: MaxValue
Subject: Re: MaxValue

Hi,

How can I pls get the maxvalue and the minvalue in a specific colunm in a
dataset or datareader.


thanks

Not sure about the datareader, but you can select datarows via critera
on a datatable using the Select method.

 

[Tom Shelton]

Sorry but I meant from the dataset or reader not from a table in the
database!!!!

I'm refereing to a DataTable object in the dataset.

DataRow[] dr = ds.Tables[0].Select ("MAX (COLUMN)");

Basically, you can filter data from a table in a dataset, not the
database.

 

[Guest]

in my table where my dataset is getting data from I have the colunms "ID" as
integer and "Valid" as Boolean and when applying the following statement :

dr = ds.Tables(0).Select("MAX(ID)")

I'm having the following error:

" Filter expression 'MAX(ID)' does not evaluate to a Boolean term"
how can I fix it?
--

--
Regads,
Rochdi

Sorry but I meant from the dataset or reader not from a table in the
database!!!!

I'm refereing to a DataTable object in the dataset.

DataRow[] dr = ds.Tables[0].Select ("MAX (COLUMN)");

Basically, you can filter data from a table in a dataset, not the
database.

 

[Tom Shelton]

in my table where my dataset is getting data from I have the colunms "ID" as
integer and "Valid" as Boolean and when applying the following statement :

dr = ds.Tables(0).Select("MAX(ID)")

I'm having the following error:

" Filter expression 'MAX(ID)' does not evaluate to a Boolean term"
how can I fix it?

 

[Tom Shelton]

in my table where my dataset is getting data from I have the colunms "ID" as
integer and "Valid" as Boolean and when applying the following statement :

dr = ds.Tables(0).Select("MAX(ID)")

I'm having the following error:

" Filter expression 'MAX(ID)' does not evaluate to a Boolean term"
how can I fix it?
--

Actually, that should be something like:

dr = ds.Tables(0).Select("ID = MAX(ID)")