how to update dataset after session cache? - Database Discussion Boards

how to use now() function in the Access when I write SQL?
look at this:
insert into table(LoginTime)values(now())
it's right?

KSCsoft

insert into table(LoginTime)values(now())

Instead of this u can use following statement

insert into table(LoginTime)values(now)

Kumar

I have a table with data from five sources, and a column specifying which one.

I need to compare this data for missing rows (Present in one source but not another one), and for different values. I would like to do this entirely in SQL.

The database is in Sybase, in which the SQL syntax differs slightly from Access (eg, no semicolons)

I having problems with getting Front Page 98’s hover buttons to function. So i need your help.i hope anyone can solve my problem qickly.please help me.i really need your help.this is the code.
Applet codes of my web page is as follow:

<applet code="fphover.class" codebase="./" width="120" height="24">
<param name="color" value="#000080" />
<param name="hovercolor" value="#0000FF" />
<param name="textcolor" value="#FFFFFF" />
<param name="text" value="C Programming" />
<param name="effect" value="glow" />
<param name="url" valuetype="ref" value="http://metalab.uniten.edu.my/~azhana/indexCProg.html" />

thank a alot to whom reply it....

Uhhh, what does this have to do with SQL / ADO / ADO.NET?

Try this forum...[^]

--EricDV Sig---------
Some problems are so complex that you have to be highly intelligent and well informed just to be undecided about them.
- Laurence J. Peters

I'm teaching myself ADO .NET, and am struggling with how to programmatically update a dataset after I have cached it and recovered it in an ASP .NET web app.

I want to use a DataAdapter to populate a DataSet, cache the DataSet in Session, then recover the DataSet in a different page, work on it, and update the database. I can populate the DataSet, cache it, recover it, and make changes. However, I cannot get the adapter.update(dataset, "table") command to work properly. Have tried multiple solutions, with multiple errors revolving around lack of INSERT commands, uninitialized connection strings, etc.

What programmatic steps must I take in a new page in order to reconnect that dataset with the origin database? Do I have to instantiate a new DataAdapter, build new commands, open a new connection, etc? Can I cache and recover any of the relevant objects (DataAdapter, SqlCommand, commandBuilder) and use them?

Here's the code to populate and cache the DataSet. It works fine (but may be excessive):

using (SqlConnection connection = new SqlConnection(connStr))
{
    try
    {
        SqlDataAdapter pointAdapter = new SqlDataAdapter();
        pointAdapter.TableMappings.Add("Table", "UserPoints");
        SqlCommand pointCommand = new SqlCommand();
        pointCommand.CommandText = "SELECT * FROM Points WHERE userID = @userID";
        pointCommand.Parameters.AddWithValue("@userID", userIDstr);
        pointCommand.Connection = connection;
        pointCommand.CommandType = CommandType.Text;
        pointAdapter.SelectCommand = pointCommand;
        SqlCommandBuilder pointCmdBuilder = new SqlCommandBuilder(pointAdapter);
        pointAdapter.Fill(ds);
        Session["UserDS"] = ds;

And here's what I'm trying to do in a different page:

dataset = (DataSet)Session["UserDS"];
// ... do some stuff to rows
using (SqlConnection connection = new SqlConnection(connStr))
{
    try
    {
        SqlDataAdapter pointAdapter = (SqlDataAdapter)Session["pointAdapter"];
        pointAdapter.Update(dataset, "UserPoints");

With this code I get a "connection string uninitialized" error. But I've gotten several different errors, enough to convince me I'm going about this the hard way. Is there a standard pattern for this sort of thing, or a tutorial someone can point me to?

In your second code you're creating the instance of the SqlConnection class (initialised with the connection string) and never use it due to the fact that SqlDataAdapter object is restored from the session state.

The standard aproach in hadling data with the ADO.NET is that simple:

*Create and open connection
*Populate and update data
*Close connection

There's no reason to store SqlConnection, DataAdapter classes because you'll not benefit from it - just recreate them when you're need them. Another hint to you - no DataAdapter neither SqlConnection is serializable therefore they're not designed to be stored persistently in the session state. To prove it right - change the session state model from "InProc" to "StateServer" or "SqlServer" and you'll get exception while putting this objects into state.

To sum up that I wrote above: don't try to cache anything from the data. When you decide to cache the data in the session state - make sure it not going to exhaust web server memory as for the every user session there'll be and cached dataset in the memory.

Best regards,

-----------
Igor Sukhovhttp://sukhov.net

Thanks Igor. As you suggested, I ditched the attempt to store SqlConnection and DataAdapter classes, and created a new insance when I needed them. It works fine now.

I am still caching the dataset, because it is relatively small and I think I'd take a bigger hit from loading it every time I need it (which is often). But I'll watch out for this as I scale my app.

the Max Size of "text" is 255,but it's so short to me.
how should I do?

thank you.

KSCsoft

if you need a larger test field, use Memo.

i want to make transaction on disconnected database what shall i do

ma_refay

You can't. You'll have to reconnect to start a transaction in the connection's context.

I'm having an issue with combining data rows returned by a query. I am working with sales data from a table joined to several other tables(confusing I know). When run the query returns multiple instances of the same company name(chain of stores), all from different areas of the country.

My question is whether or not there is a way to combine all the data for one company name and be able to get totals for ie: price, # of sales, etc. I've tried using a group by statement, but as I need all the column data from the original table I'm having to group by every column name.

Thanks.

Cheers,
Lil Turtle

If you are using SQL server then the best idea is to have a view which will return all company names. Once you are done with this you can write another SQL select on view with group by clause for any further data selection.

Hope this helps.

Difficult - > Challenging, this simple replacement made me take my life little easy;)

A view in this instance is not needed as the data returned is for a report that I'm doing and not part of a permanent data store. Thanks for the tip though I can apply this to other endevors.;)
And I do appreciate the help, Thanks.

A humble novice,
Lil Turtle

Lil Turtle wrote:
I am working with sales data from a table joined to several other tables(confusing I know).

Not really - Joining tables will be a regular occurrance if your database is normalised properly.

Lil Turtle wrote:
My question is whether or not there is a way to combine all the data for one company name and be able to get totals for ie: price, # of sales, etc. I've tried using a group by statement, but as I need all the column data from the original table I'm having to group by every column name.

Then what you might try to do is to perform the GROUP BY in a subquery and then join the subquery to the table which contains all the other data that you want. If you want an example, you might like to show your existing code.

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The GROUP BY in the sub query worked like a dream. Thanks for the response, I appreciate the help.

A humble novice,
Lil Turtle

I am only one administator of SQL 2005 database , I want to divide database in seven administration levels !

GETEL - General Telecom

GETEL - General Telecom wrote:
I am only one administator of SQL 2005 database , I want to divide database in seven administration levels !

Good on you! Keep up the great work!

I presume you wanted to ask a question.... And I presume that question is "How do I divide the database into seven administration levels?"

My question is return is: What do you mean by an "administration level"?

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Colin Angus Mackay wrote:

My question is return is: What do you mean by an "administration level"?

Thank you, Colin. I don't quite follow what GETEL - General Telecom is asking for. Would this be different user roles?

Paul Conrad wrote:
Would this be different user roles?

I suppose it could be.

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Hi - We have a particular field called "EventNum" which is written to a whole bunch of tables. I am new to this group and table struture.

Is there a way I can select out this value from across all the tables in a particular database.

something like - "select * from dbo.* where eventnum=11111111"

this same info is spanned across many tables.

many thanks.

VK-Cadec wrote:
Is there a way I can select out this value from across all the tables in a particular database

No, you have to select the tables individually because each will likely have a different shape even if they do share a common column. In one table this column will likely be the primary key. In other tables it will likely be a foreign key.

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* .NET debugging, tracing and instrumentation by Duncan Edwards Jones and Code Coverage in .NET by Craig Murphy
* Developer Day Scotland: are you interested in speaking or attending?
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