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I need help i am trying to creat a program in VB.net for a pda.
i already have the database created using the quary analizer.
but i can not get the connection to work.
Public Sub conn()
Dim conn As New SqlCeConnection
conn.ConnectionString = "Provider=Microsoft.SQLSERVER.OLEDB.CE.2.0; Data Source=\My Documents\abook.sdf;"
end sub
but i keep getting exceptions
i have searched threw several examples but they all start out by creating the database or using XML.
all i want is to retrieve data and manipulate it.
please some one explane what i am doing wrong, and a good example of what i need to do.
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what is the error being reported in the exception?
And don't you need some kind of authentication in the connection string?
Absolute faith corrupts as absolutely as absolute power
Eric Hoffer
The opposite of the religious fanatic is not the fanatical atheist but the gentle cynic who cares not whether there is a god or not.
Eric Hoffer
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I've made a table in access with a columnfield "searchdate"
Now I want to filter rows between two dates in the columnfield "searchdate" using two datetimepickers. I'm using the (configure)oldedbadapter with the querybuilder with the following SQL-expression :SELECT...FROM...WHERE ([searchdate] >= ?) AND ([searchdate] <= ?)
My code : oledbdataAdapter.selectCommand.parameters("searchdate").value = datetimepicker1.value.date
oledbdataAdapter.selectCommand.parameters("searchdate").value = datetimepicker2.value.date
dataset.clear
oledbdataadapter.fill(dataset)
result: it doesn't work!!!
if I'm using the expression select....from...where ([searchdate] >= ?)and ([searchdate]<= #01/12/2005#)he finds the records beween a date chosen with the datetimpicker1 and the date 01/12/2005.
Can somebody help me how to find rows beween two dates using two datetimepickers bound two one columnfield "searchdate"
Thank you very much for answering to my question.
Boutie
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You are giving both dates the same parameter name, so the result is that you are asking for all the records between the same dates: dateTimePicker2 is 5-9-2004 then the query becomes: select...from...where [searchdate] >= #05/09/2005# and [searchdate] <= #05/09/2005#
Instead of using the field name as a parameter name, use some arbitrary names like p1,p2 so each of the two parameters in your query have different names. add tem to the parameters collection and set their values in the order they will be used in the query (the oledb layer doesn't care about the parameter names, just the order; but the .Net collection object (the parameters collection of the query) wants unique parameter names)
Absolute faith corrupts as absolutely as absolute power
Eric Hoffer
The opposite of the religious fanatic is not the fanatical atheist but the gentle cynic who cares not whether there is a god or not.
Eric Hoffer
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Hi all,
how can I get the new id after adding a new DatRow when I'm working with an (offline) Dataset. Which sql command is to use for ?
(or is there an other command ?)
I am working with
MissingSchemaAction.AddWithKey
("SELECT @@IDENTITY") is asking the (online) Database and not the Dataset, isn't it ?
thanks
regards
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It's asking the database.
Absolute faith corrupts as absolutely as absolute power
Eric Hoffer
The opposite of the religious fanatic is not the fanatical atheist but the gentle cynic who cares not whether there is a god or not.
Eric Hoffer
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Thank you for this info,
but what's the way working with offline tables and getting the new id after adding a row?
regards
Frank
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There is no way to get a new identity key when working offline. Only the server knows what its next identity will be.
It is best to rethink your design and use UniqueIdentifiers (GUIDs) in place of your identity keys. They can be developed on the client without clashing with keys on the server.
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Hi Michael,
that's a good idea, and I will follow that way in the future. But I think I found a way for my problem but I'm not shure if it always works fine.
...
I placed an eventhandler in the data_new routinem like that:
Table.RowChanged += new DataRowChangeEventHandler(Table_RowChanged);
...
private void Table_RowChanged(object sender, DataRowChangeEventArgs e)
{
if(e.Action.ToString() == "Add")
{
Console.WriteLine("index1 = " + e.Row["id"].ToString());
}
}
// The dataset in the database is locked to prevent changes from other users.
Thank's
Frank
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For an absolute beginner, the books online that come with SQL Server are pretty good, actually. However, I have The programmers guide to SQL and found it very helpful. Then I bought the guru's[^] guides, although I'm far from a guru, I at least have a good source of info when I need to pretend to be....
Christian Graus - Microsoft MVP - C++
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Christian Graus wrote:
the books online that come with SQL Server are pretty good
I do not have SQL Server. I have played with MySQL, MSDE, Access, and SQLite, but I want to get beyond the basic playing and learn how to actually do something. Thanks for the link to the guru's books, looks like they would also make an interesting addition to my book shelf.
As an aside, the link you gave me to amazon.com lists it's prices in US dollars does it not? The price they are quoting for the box set is $98.86. I looked up the same box set on chapters.ca and they are quoting $97.99 CDN. With the exchange what it is I would save 20% by buying the set from chapters instead of from amazon. Not only that, but chapters gives free shipping.
"You're obviously a superstar." - Christian Graus about me - 12 Feb '03
"Obviously ??? You're definitely a superstar!!!" - mYkel - 21 Jun '04
"There's not enough blatant self-congratulatory backslapping in the world today..." - HumblePie - 21 Jun '05
Within you lies the power for good - Use it!
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MSDE is Sql server. SQL Books On line can be downloaded here.[^]
Absolute faith corrupts as absolutely as absolute power
Eric Hoffer
The opposite of the religious fanatic is not the fanatical atheist but the gentle cynic who cares not whether there is a god or not.
Eric Hoffer
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Thanks for the link Rob, I am downloading right now
"You're obviously a superstar." - Christian Graus about me - 12 Feb '03
"Obviously ??? You're definitely a superstar!!!" - mYkel - 21 Jun '04
"There's not enough blatant self-congratulatory backslapping in the world today..." - HumblePie - 21 Jun '05
Within you lies the power for good - Use it!
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I have an sql table with many varchar columns and the row size exceeds 8000 max.
If I redesign the table to make the lengthy columns to text data type, what are the implications on the data?
any other issues?
TIA.
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If the rows that are changed to text are rarely used - you may see a speed increase. If they are heavily used, then you may see a speed decrease. Client code won't need to change that much. There are more restrictions in Stored Procs on the manipulation of Text Fields.
Text fields are stored in a seperate place from rest of the table data. Therefore, it takes a minimum of 2 IOs for the SQL Server build a query result that contains a text field.
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A better approach would be to take a hard look at the table design, and see if you can split the table into several smaller ones.
Text (or NText) columns can't be used in 'Like' queries (you would have to use ful text search) and they will introduce a performance hit, since the data is stored in a binary tree rather than in the table (the table will only contain a pointer to the root of the tree). this results in at least one additional disk IO for each field returned (possibly more if the field was large, and had to span several allocation nodes on the storage tree).
Certainly you have more data per row than can easily be displayed, so I would think multiple tables with a common foreign key would work.
Absolute faith corrupts as absolutely as absolute power
Eric Hoffer
The opposite of the religious fanatic is not the fanatical atheist but the gentle cynic who cares not whether there is a god or not.
Eric Hoffer
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Thanks all.
I agree to the idea of spliting the table with foreign Key relations
than changing to text fields.
thanks again.
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Hi,
I have a foxpro dbf file and I want to copy the data from mdf to sql server,
how can I ? I have tried through the sql server Import wizard but failed to
do this....Pls help
Thanks
Ram
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Try the Data Transformation Services import/Export wizard of the sql server and choose the correct data source.
Does it work!
phokojoe
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Hi,
Anyone got source code to change SQl Server startup account to SA.
I need this to be run in my installation.
VB script, java script or installscript will be very helpful.
Thanks
Toms
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Help me
I have a trouble again with M.Access. I have a combo-box on a form, and this combo-box has the responsibility on showing the Query which creates the 4-column table, including Company,Name,Address and ClientID.
My purpose is that I want to show this Query in the combo-box in the order A-Z, before the blank company items.
My solution:
I create a query like below:
select .........
from nhanvien
where company is null
union
select .........
from nhanvien
where company is not null
However, the result isn't right like my hope. I think that the reason is because of the order of the ClientID which is the primary key...As a result, the destination query automatically sorts on the ClientID order.
Thinking of the solution :
I don't know how to do to archieve that result. I think so much about the SQL sentence of the above query. I believe that there's another SQL sentence helping me to solve this problem. I'm very happy whether you give me a SQL sentence to do that or another solution to obtain the same result ....
Thanks so much <vtalau>
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<br />
Select Company,... from nhanvien where company is NOT NULL<br />
Union<br />
Select Company,... from nhanvien where company is NULL<br />
order by Company ASC<br />
<br />
This wont quite accomplish what you wan, the null values will sort to the top, not the bottom, but at least the non-null values will be sorted a-z for you.
an alternative would be to do this in two steps:
selecting all the not-null records first:
<br />
Select Company,... from nhanvien where company is NOT NULL order by company ASC<br />
and add the records to the combo box
then add the remaining values with a second query not sorted
<br />
Select Company,... from nhanvien where company is NULL <br />
and add the results to the combo (don't clear the first set of results)
Absolute faith corrupts as absolutely as absolute power
Eric Hoffer
The opposite of the religious fanatic is not the fanatical atheist but the gentle cynic who cares not whether there is a god or not.
Eric Hoffer
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