1.   Connection String needs to be customizable by users during runtime.
2.   Source of Connection String can be changed programmatically.
3.   Tables can be modified by users.
4.   Use table adapters or use data adapters
5.   How to update all data tables for all datasets with changes in a 
Windows Form without specifying dataset?

Not completely data "access" issues.

"Peter"  wrote in message 
news:A4A15CF3-3EE3-404C-8CA9-ACCCAF8D8955@microsoft.com...

> 1.   Connection String needs to be customizable by users during runtime.


This is not a major issue, as you can use a singleton for connection and 
change at the user's whim. If you want to save back the connection string, 
it is a bit more of an issue if you are using web.config alone, but it is 
not insurmountable, as you can add auxiliary files with your own config 
information.


> 2.   Source of Connection String can be changed programmatically.


Source of connection string? You mean sometimes it comes from config, 
sometimes from metadata tables, sometimes from XML files, sometimes from 
user input? Or, do you mean you need to be able to change the connection 
string using code?

If the former, set up a factory pattern with different options that are 
available and you can then use the correct factory based either on config or 
user input.

If the later, shy away from TableAdapters in 2.0, unless you want to edit 
the code created to allow you access. In 3.5 (VS 2008, formerly Orcas) the 
field opens up.


> 3.   Tables can be modified by users.


To alter actual data tables, use SMO.


> 4.   Use table adapters or use data adapters


Table Adapters are cool, but a pain for the flexibility you require during 
run time.


> 5.   How to update all data tables for all datasets with changes in a
> Windows Form without specifying dataset?


I am not sure I understand this. Any time you open a table, you will have a 
dataset. As long as you know which database you are currently using 
(singleton config information?) and have the dataset, you can fire off an 
update. Am I missing something?

-- 
Gregory A. Beamer
MVP; MCP: +I, SE, SD, DBA
http://gregorybeamer.spaces.live.com
Co-author: Microsoft Expression Web Bible (upcoming)

************************************************
Think outside the box!
************************************************

Hi Gregory,

Thanks for your post. 

For my questions #1 and #2:

I need to able to change the connection string using code and the changes 
need to be saved.  For example, I need the connection point to a production 
MS SQL Server instead of development MS SQL Server.  Another example, I need 
to connect to a different database.   

My understanding is that the connection string information is stored in 
app.config by default. So, the question is how to read/write that 
information.   It seems that I may able to use ConfigurationManager class to 
do that.

Peter

"Cowboy (Gregory A. Beamer)" wrote:


> Not completely data "access" issues.
> 
> "Peter"  wrote in message 
> news:A4A15CF3-3EE3-404C-8CA9-ACCCAF8D8955@microsoft.com...
> > 1.   Connection String needs to be customizable by users during runtime.
> 
> This is not a major issue, as you can use a singleton for connection and 
> change at the user's whim. If you want to save back the connection string, 
> it is a bit more of an issue if you are using web.config alone, but it is 
> not insurmountable, as you can add auxiliary files with your own config 
> information.
> 
> > 2.   Source of Connection String can be changed programmatically.
> 
> Source of connection string? You mean sometimes it comes from config, 
> sometimes from metadata tables, sometimes from XML files, sometimes from 
> user input? Or, do you mean you need to be able to change the connection 
> string using code?
> 
> If the former, set up a factory pattern with different options that are 
> available and you can then use the correct factory based either on config or 
> user input.
> 
> If the later, shy away from TableAdapters in 2.0, unless you want to edit 
> the code created to allow you access. In 3.5 (VS 2008, formerly Orcas) the 
> field opens up.
> 
> > 3.   Tables can be modified by users.
> 
> To alter actual data tables, use SMO.
> 
> > 4.   Use table adapters or use data adapters
> 
> Table Adapters are cool, but a pain for the flexibility you require during 
> run time.
> 
> > 5.   How to update all data tables for all datasets with changes in a
> > Windows Form without specifying dataset?
> 
> I am not sure I understand this. Any time you open a table, you will have a 
> dataset. As long as you know which database you are currently using 
> (singleton config information?) and have the dataset, you can fire off an 
> update. Am I missing something?
> 
> -- 
> Gregory A. Beamer
> MVP; MCP: +I, SE, SD, DBA
> http://gregorybeamer.spaces.live.com
> Co-author: Microsoft Expression Web Bible (upcoming)
> 
> ************************************************
> Think outside the box!
> ************************************************ 
> 
> 
>