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Hai,
I want to get the last 10 records from a table containing 100 records.What will be the siplest SQL query ,I can use for retreiving last 10 records,without giving any conditions.I am sure somebody can show my way.
Thank you,
Rahul.
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This is the best I can come up with:
SELECT TOP 10 FROM MyTable ORDER BY ClusteredIndexColumns DESC
Remember that the SELECT statement returns a set, and in a set there is no concept of order, so, in order to maintain this artificial order, to get the first 10 rows chance the DESC to ASC
The ClusteredIndexColumns are the columns that make up your clustered index, this is often the primary key.
My: Blog | Photos
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Hai Colin,
Great.That seems to be the best and simplest way.Thank you very much for your valuable information and for the fantastic help.
Thank you,
Rahul
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I want to know who i can access specif rows in dataset to generate values in other rows: for example, if i ve in forst row [A1 , A2 , A3] and in the second row i ve to calculate value like this [ A5, A4-A2 , A5-(A4-A2)]
remark that A2 from pervious row , i means i need to know how to loop on dataset records in reporting services
need solution as soon as possible
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Hi
Does anyone know how you check to see if a table in a database allready exists?
Hehe. Maybe I should give some more information here:
I have a direct connection to a Access Database via a OleDB Connection, and I am programming in C#.
Wilye
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i also use this one, but never tested on MS SQL Server (i use Oracle DB) :
select table_name
from user_tables
order by table_name asc;
cheers,
TOXCCT >>> GEII power
[toxcct][VisualCalc]
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DataTable schemaTable = MyoledbConnection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables_Info,
new object[] {null, null, null, "TABLE"});
//The schema table's third column contains the Table Names.
//Explore this Table and the commands.
Cheers,
Akos
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YES. That worked. Thanks
Wilye
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Hi. I have a webform that has several dropboxes that are dynamically populated from a ms access database. Im fairly new to database design. In my drop boxes i have add a "All" Item. which will allow me to search the database for all records.
my problem is:
Drop box one is listing several industries. (independant)
Drop box two lists several uses ( which dynamically change based on the industry selected)
Drop box 3 lists categories (independant)
drop box 4 lists options based on the selected category
I want to be able to search my table for records that match all of the user selected criteria.
im trying to use parameters and I cant figure out the best way to do this... I know what ive done probably isn't the best way to do this... but this is an example of how im creating my query string.
Sub CreateQuery()
Dim SelectPhotos As OleDbCommand
Dim Photo As OleDbDataReader
Dim strSelect As String
Dim SelectedIndustry As String
Dim SelectedUse As String
Dim SelectedCategory As String
Dim SelectedOption As String
strSelect = "Select * From Catalog1 Where "
SelectedIndustry = dropIndustry.SelectedItem.Value
SelectedUse = dropUse.SelectedItem.Value
SelectedCategory = dropCategory.SelectedItem.Value
SelectedOption = dropOption.SelectedItem.Value
SelectPhotos = New OleDbCommand(strSelect, conPhoto)
If SelectedIndustry > 0 Then
SelectPhotos.Parameters.Add("@selectedIndustry", SelectedIndustry)
strSelect += "IndustryID=@SelectedIndustry And "
End If
If SelectedUse > 0 Then
SelectPhotos.Parameters.Add("@selectedUse", SelectedUse)
strSelect += "UseID=@SelectedUse And "
End If
If SelectedCategory > 0 Then
SelectPhotos.Parameters.Add("@selectedCategory ", SelectedCategory)
strSelect += "CategoryID=@SelectedCategory And "
End If
If SelectedOption > 0 Then
SelectPhotos.Parameters.Add("@selectedOption ", SelectedOption)
strSelect += "OptionID=@SelectedOption"
End If
conPhoto.Open()
Photo = SelectPhotos.ExecuteReader()
Photo.Close()
conPhoto.Close()
lblTest.Text = strSelect
End Sub
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Hi
i have a oledbcommand with parameter:
"insert into T(a,b) values (@a,@b);"+"select @@IDENTITY as '" + "a" + "'";
.
.
.
add CommandParameters
.
.
.
then
.
.
.
int retValue = oleDbCommand.ExecuteScalar();
.
.
.
but i get error :
Characters found after end of SQL statement
What should i do
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WDI wrote:
"insert into T(a,b) values (@a,@b);"+"select @@IDENTITY as '" + "a" + "'";
This is nuts. Why are you concatenating string literals like this? You could do all this in one literal string:
insert into T(a,b) values (@a,@b);select @@IDENTITY as 'a' And as you can see this is much easier to read. I suspect there is something more going on here because you are unlikely to have a table named T with columns name a and b. So, we cannot see what your proper string is, which is the cause of your problem, because you have chosen to obfuscate it. This does not help us help you. If you need to obfuscate parts of the code then do that to code that is incidental to the problem, not directly related to it.
Next, what is this as 'a' on the end. I'm guessing this will confuse the query parser because the apostrophe is for string literals in SQL, not for naming columns. Use [a] or "a" - better yet, because you are using ExecuteScalar, don't name the column at all.
My: Blog | Photos
WDevs.com - Open Source Code Hosting, Blogs, FTP, Mail and More
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hello dear,
I want to register the server from my local enteprize manager .bu this error apeared :
the server doesn't exist or access is denied
I called the manager of the server he said the server have 20 sites that working properly with out problem.and you should setting the control pannel of your local computer.what setting?how?
thanks in advanced.
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If you have any adea please tell me?
thanks in advanced.
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I want to take all the data from a column of a table. Foreach value i get, I used it as a field to my insert function into another table . I some kind like
for(int i=0;i
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Yes, you could do it very easily like this:
string sql = "INSERT INTO Table2 VALUES (@value1, .....)";
SqlCommand cmd = new SqlCommand(sql, conn);
cmd.Parameters.Add("@value1", SqlDbType.Int);
foreach(DataRow row in table1.Rows)
{
cmd.Parameters[0].Value = row[1];
cmd.ExecuteNonQuery();
}It can be done with a stored procedure in the same way, only if you change the sql variable to the name of a stored procedure that takes one parameter named value1.
I hope it helps.
-- LuisR
Luis Alonso Ramos
Intelectix - Chihuahua, Mexico
Not much here: My CP Blog!
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I means that we'll do all that things in a single store procedure, not in C# (include the way we take each row from a table). And then, in C#, we just call that store procedure to execute automatic. Can you help me?
Thanks your reply. 
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Ah I see. You could try this:
INSERT INTO Table2 (valueFromTable, fixedColumn1, ...) SELECT column1, fixedValue1 ... FROM Table1 I'm no SQL expert, but if I remember correctly, I once used something like that to copy a table.
-- LuisR
Luis Alonso Ramos
Intelectix - Chihuahua, Mexico
Not much here: My CP Blog!
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it won't work until you don't provide a values statement into your insert
TOXCCT >>> GEII power
[toxcct][VisualCalc]
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Yes, it works. I've used the following statement in a stored procedure:
INSERT INTO Shutters(ID_pedido, Fabricado, Precio, Descripcion, Tipo, Madera, Color, Acabado)
(
SELECT @ID_pedido, 0, Precio, Descripcion, Tipo, Madera, Color, Acabado
FROM Cotizacion_Shutters
WHERE ID_pedido = @ID
)</code>and it works as expected, copying some records from one table to another with most columns the same, and changing only the values of one column (Fabricado, set to 0).
-- LuisR
Luis Alonso Ramos
Intelectix - Chihuahua, Mexico
Not much here: My CP Blog!
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Wow, it's too strange and really interesting  . I've never seen it before (even in SQL Help). You're right, it really works... Thanks a lot!
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Blue_Skye wrote:
You're right, it really works...
I know, I learned it here! 
I'm glad to have helped you. Good luck!
-- LuisR
Luis Alonso Ramos
Intelectix - Chihuahua, Mexico
Not much here: My CP Blog!
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I've just found the solution. The way i solve the problem is using cursor :
declare @VariableName datatype<br />
declare CursorName<br />
for<br />
select TableColumn from Table1<br />
open CursorName<br />
fetch next from CursorName into @VariableName<br />
while(@@FETCH_STATUS = 0)<br />
begin<br />
Insert into Table2 values(@VariableName,...,...)<br />
fetch next from CursorName into @VariableName<br />
end<br />
close CursorName<br />
deallocate CursorName
The example i used here take just one column but you can use as many columns as you like. This cursor remind me while(Reader.Read()) in C#
Thanks your reply. I'm very happy to talk with you
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I'm glad you solved it, but cursors are very inefficient. I would recommend you at least try my idea, it should work much faster. See my response to toxcct above; the code I gave you works.
-- LuisR
Luis Alonso Ramos
Intelectix - Chihuahua, Mexico
Not much here: My CP Blog!
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Hello,
When l got to update my database l get this error message "Missing the datacolumn 'DepartmentName' in the DataTable 'Employee' for the sourceColumn 'DepartmentName' ".
I have a database application. 2 tables. Department and Employee.
Department -> DepartmentCode (PK)
DepartmentName
Employee -> EmployeeID (PK)
Name
Surname
DepartmentCode (FK)
I have create this relationship in code using relationships in the form load event. see below:
<br />
private void frmEmployees_Load(object sender, System.EventArgs e)<br />
{<br />
try<br />
{<br />
cnn.Open();<br />
OleDbCommand cmd = cnn.CreateCommand();<br />
cmd.CommandType = CommandType.Text;<br />
cmd.CommandText = "SELECT * FROM Employee";<br />
da.SelectCommand = cmd;<br />
da.FillSchema(ds,SchemaType.Source,"Employee");<br />
da.Fill(ds,"Employee");<br />
<br />
cmd.CommandText = "SELECT * FROM Department";<br />
da.SelectCommand = cmd;<br />
da.FillSchema(ds,SchemaType.Source,"Department");<br />
da.Fill(ds,"Department");<br />
<br />
DataColumn parentColumn = ds.Tables["Department"].Columns["DepartmentCode"];<br />
DataColumn childColumn = ds.Tables["Employee"].Columns["DepartmentCode"];<br />
<br />
ds.Relations.Clear();<br />
drEmployees = new DataRelation("EmployeeDetails",parentColumn,childColumn);<br />
ds.Relations.Add(drEmployees);<br />
<br />
txtEmployeeID.Text = ds.Tables["Employee"].Rows[0]["EmployeeNumber"].ToString();<br />
txtFirstName.Text = ds.Tables["Employee"].Rows[0]["FirstName"].ToString();<br />
txtSurname.Text = ds.Tables["Employee"].Rows[0]["Surname"].ToString();<br />
txtDateOfBirth.Text = ds.Tables["Employee"].Rows[0]["DateOfBirth"].ToString();<br />
txtAddress1.Text = ds.Tables["Employee"].Rows[0]["Address1"].ToString();<br />
txtAddress2.Text = ds.Tables["Employee"].Rows[0]["Address2"].ToString();<br />
cboDepartment.Text = ds.Tables["Employee"].Rows[0]["DepartmentCode"].ToString();<br />
<br />
string departmentCode = ds.Tables["Employee"].Rows[0]["DepartmentCode"].ToString();<br />
DataRow[] departmentRow = ds.Tables["Department"].Select("DepartmentCode = '" + departmentCode + "' ");<br />
string departmentName = departmentRow[0]["DepartmentName"].ToString();<br />
<br />
<br />
this.UpdateDepartments();
} <br />
catch ( OleDbException ex )<br />
{<br />
MessageBox.Show(ex.Message);<br />
}<br />
catch ( Exception ex )<br />
{<br />
MessageBox.Show(ex.Message);<br />
}<br />
}<br />
When l click the update button, l run this code and get an error on the update.
<br />
ds.Tables["Employee"].Rows[0]["FirstName"] = txtFirstName.Text;<br />
ds.Tables["Employee"].Rows[0]["Surname"] = txtSurname.Text;<br />
ds.Tables["Employee"].Rows[0]["DepartmentCode"] = departmentCode;<br />
<br />
da.Update(ds,"Employee");
I hope someone can help me with this question. very important.
Thanks in advance,
Steve
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