Database

13-Feb-04 8:08

Hi all,

I have an OleDbConnection object and I would like to be able to get a list of all the tables and views available through it.

Do I need to know anything about the underlying database architecture to do this? For example, if it were mssql, I would know to query sysobjects. But if I do not know where the underlying database stores the data am I SOL?

I suspect the answer is "no" because I can get a list of tables and views when I add this data connection to my server explorer in VS.NET but I haven't a clue how the do it in code.

Thanks in advance,
Bill

-Dr_X-13-Feb-04 14:27

-Dr_X-

13-Feb-04 14:27

The easiest way is to use the following query.

Select name, type from Sysobjects
where	type = 'U' 
or type = 'V'

The other way is to use ADOX. However, I have not used it in .Net only in the old VB world.

Michael

Bill Dean13-Feb-04 15:08

13-Feb-04 15:08

Michael,

Thanks for the response! I did not realize it was that easy.

Bill

-Dr_X-13-Feb-04 15:36

-Dr_X-

13-Feb-04 15:36

I would recommend doing this from a stored procedure.
Really don't want users messing around with sysobjects unless there very knowlegeable.

Michael

Bill Dean13-Feb-04 15:43

compare time part of datetime field

13-Feb-04 15:43

If I had sql server on the back-end...I would. But we are trying to get at data in Informix...which as far as I know doesn't support sprocs.

Like I said before, I really a complete novice with this particular back-end so I was looking for a way to do this that generalized to all ado.net.

Your suggestion works great btw, even with the Informix back-end. Thanks again.

Bill

asd175313-Feb-04 7:15

asd1753

13-Feb-04 7:15

hi how can i compare time part of datetime field, for exaple :
time of datetimefield between '12:24:36' and '18:50:25'
thank you Rose | [Rose]

precentage of loading data in Dataset

Saeed Tabrizi13-Feb-04 5:43

Saeed Tabrizi

13-Feb-04 5:43

Please Tell to me how can i make a progress bar control for showing the loaded data ine dataset or all data in any winforms.
cause this work is easy in the ado classic .
but i cant find any method or event or object for this problem .

so thanks
Saeed Sa_tabrizi@yahoo.com Smile | :)

"Select top" command

dlhson212-Feb-04 19:21

dlhson2

12-Feb-04 19:21

I cannot create a stored procedure like that:

CREATE PROCEDURE sp_GetLatestNews<br />
@nCount int<br />
AS<br />
	Select top @nCount * from NEWS <br />
GO

But I CAN do like that:

CREATE PROCEDURE sp_GetLatestNews<br />
@nCount int<br />
AS<br />
	Select top 5 * from NEWS <br />
GO

How can I throw a parameter to "Select TOP" command Confused | :confused:

=======================
Nothing is perfect

Motyka12-Feb-04 20:52

Motyka

12-Feb-04 20:52

CREATE PROCEDURE sp_GetLatestNews
@nCount int
AS
SET ROWCOUNT @nCount
Select * from NEWS
SET ROWCOUNT 0
GO

basementman13-Feb-04 5:58

basementman

13-Feb-04 5:58

CREATE PROCEDURE sp_GetLatestNews
@nCount int
AS
declare @cCount varchar(10)
select @cCount = Convert(varchar(10),@nCount)
exec ('select top ' + @cCount + ' * from NEWS')
GO

onwards and upwards...

Bruce Duncan13-Feb-04 6:49

Bruce Duncan

13-Feb-04 6:49

As the other two replies mentioned, you can use the SET ROWCOUNT statement or construct and execute a sql statement dynamically.

But I read the other day the Yukon will allow expressions to be used as an argument to the TOP statement.

This is from http://msdn.microsoft.com/msdnmag/issues/04/02/TSQLinYukon/default.aspx[^]

"The T-SQL TOP option in Yukon has two significant enhancements. You can now specify as an argument to TOP an expression that can contain variables or even a self-contained query. You can also use the TOP option with modifying DML (INSERT, UPDATE, DELETE).

To specify an expression, you must enclose it in parentheses. The expression should be of the BIGINT datatype when not using the PERCENT option, and a float value in the range 0 through 100 when using the PERCENT option. The following code shows how to use an expression with a variable to return the requested number of earliest orders from the SalesOrderHeader in the AdventureWorks database:"

USE AdventureWorks

DECLARE @n AS BIGINT
SET @n = 5

SELECT TOP (@n) *
FROM SalesOrderHeader AS SOH
ORDER BY OrderDate, SalesOrderID

Searching the web without Google is like straining sewage with your teeth.
Userfriendly, 2003/06/07

dlhson213-Feb-04 17:01

dlhson2

13-Feb-04 17:01

I wondered that what is faster in executing?

CREATE PROCEDURE sp_GetLatestNews <br />
@nCount int <br />
AS <br />
SET ROWCOUNT @nCount <br />
Select * from NEWS <br />
SET ROWCOUNT 0 <br />
GO

CREATE PROCEDURE sp_GetLatestNews <br />
@nCount int <br />
AS <br />
declare @cCount varchar(10) <br />
select @cCount = Convert(varchar(10),@nCount) <br />
exec ('select top ' + @cCount + ' * from NEWS') <br />
GO

And what is T-SQL ? Help me !

=======================
Nothing is perfect

Can I execute a DTS package from T-SQL?

Hesham Amin13-Feb-04 23:03

Hesham Amin

13-Feb-04 23:03

I believe that the first is faster
It gives SQL server the ability to comiple the SP and save it
but in second case ,, a query is constructed on the fly and then it will be parsed.

T-SQL = Transact SQL ( the language used in SQL Server )

Thesisus12-Feb-04 5:24

Thesisus

12-Feb-04 5:24

It'd really make this project simple if i could, but this part doesn't appear to be as easy I thought.

Re: Can I execute a DTS package from T-SQL?

Jeff Martin12-Feb-04 10:50

Jeff Martin

12-Feb-04 10:50

You could use a combination of xp_cmdshell extended stored procedure and the dtsrun utility. Look in the BOL for the dtsrun utility, it's a command line program to execute DTS packages.

Jeff Martin
Triple20 Software

grant permission to access the Msysobjects

Daminda12-Feb-04 2:53

Daminda

12-Feb-04 2:53

I need to know how can we grant permission to access the Msysobjects through C# coding.

Any kind of suggestion is highly appreciated!

Re: grant permission to access the Msysobjects

Mazdak12-Feb-04 3:30

Mazdak

12-Feb-04 3:30

Daminda wrote:
Any kind of suggestion is highly appreciated!

You won't get the answer by reposting and reposting each day.

Daminda wrote:
I need to know how can we grant permission to access the Msysobjects through C# coding.

I don't know if it helps but maybe you have to login with windows adminstrator account to do that.

Mazy

"Improvisation is the touchstone of wit." - Molière

Data out of large File into MS Access DB

93Current12-Feb-04 2:50

93Current

12-Feb-04 2:50

Hi,

I have no idea anymore...

there is a file named 'fdax.txt' and a MS Access DB with an existing table 'data_table'. I have created a void 'ReadWriteData()' that should read out the data from the file which contains maybe hundreds of lines and insert them into the 'data_table'. My StreamReader works right, the SQL-Syntax is ok. but not more than 30 lines of data will be inserted into 'data_table' before there comes up an OleDbException: Overflow. After clicking OK it will be continued and some lines will be inserted. Then a new OleDbException: Overflow... OK... some lines... Overflow... OK... some lines till the end of loop.

Can anyone help me?

Here is the code of my 'ReadWriteData()':

private void ReadWriteData()<br />
{<br />
	StreamReader datei;<br />
	datei = new StreamReader("fdax.txt", Encoding.ASCII, true,1);<br />
<br />
	string zeile;<br />
	string[] felder;<br />
<br />
	int id = 1;<br />
	while (datei.Peek() != -1)<br />
	{<br />
		zeile = datei.ReadLine();<br />
		felder = zeile.Split(new char[] {','});<br />
<br />
		string datumzeit = felder[1] + felder[2];<br />
		string strOpen = felder[3];<br />
		string strHigh = felder[4];<br />
		string strLow = felder[5];<br />
		string strClose = felder[6];<br />
		string strVolume = felder[7];<br />
<br />
		string strJahr = datumzeit.Substring(0, 4);<br />
		int jahr = Convert.ToInt16(strJahr);<br />
		string strMonat = datumzeit.Substring(4, 2);<br />
		int monat = Convert.ToInt16(strMonat);<br />
		string strTag = datumzeit.Substring(6, 2);<br />
		int tag = Convert.ToInt16(strTag);<br />
		string strStunde= datumzeit.Substring(8, 2);<br />
		int stunde = Convert.ToInt16(strStunde);<br />
		string strMinute= datumzeit.Substring(8, 2);<br />
		int minute = Convert.ToInt16(strMinute);<br />
		string strSekunde= datumzeit.Substring(8, 2);<br />
		int sekunde = Convert.ToInt16(strSekunde);<br />
		convertdatumzeit = new DateTime(jahr, monat, tag, stunde, minute, sekunde, 0);<br />
		string strDatum = Convert.ToString(convertdatumzeit);<br />
		string strId = Convert.ToString(id);<br />
<br />
		string strInsertIntoMDB = "insert into data_table(id, datum, [open], high, low, [close], volume) values(";<br />
			strInsertIntoMDB += ToSQL(strId) + ", '";<br />
			strInsertIntoMDB += ToSQL(strDatum) + "', ";<br />
			strInsertIntoMDB += ToSQL(strOpen) + ", "; <br />
			strInsertIntoMDB += ToSQL(strHigh) + ", "; <br />
			strInsertIntoMDB += ToSQL(strLow)+ ", "; <br />
			strInsertIntoMDB += ToSQL(strClose) + ", "; <br />
			strInsertIntoMDB += ToSQL(strVolume) + ")";<br />
		oleDbCommand1 = oleDbConnection1.CreateCommand();<br />
		oleDbCommand1.CommandText = strInsertIntoMDB;<br />
		try<br />
		{<br />
			oleDbConnection1.Open();<br />
			oleDbCommand1.ExecuteNonQuery();<br />
			oleDbCommand1.Dispose();<br />
			oleDbConnection1.Close();<br />
		}<br />
		catch(Exception ed)<br />
		{<br />
			MessageBox.Show("Error in inserting! "+ed.ToString(), "Error");<br />
		}<br />
		id++;<br />
	}			<br />
		<br />
}<br />
<br />
private string ToSQL( string input )<br />
{<br />
	return input.Replace( "'" , "''" ); <br />
}

Re: Data out of large File into MS Access DB

Bill Dean13-Feb-04 3:18