I am using dropdown list values Bound from data base my code
Public Function get_type() As String
'get type
If IsPostBack = False Then
da = New OleDbDataAdapter("select (type) from prod_type", con)
da.Fill(ds, "prod_type")
ddtype.DataSource = ds
ddtype.DataTextField = "type"
ddtype.DataValueField = "type"
ddtype.DataBind()
da.Dispose()
ds.Dispose()
con.Close()
End If
I call this function in page load
Edit: ignore this, it's wrong:
This is a SQL question not a asp.net or VB question.
Your sql won't select unique 'types' from your prod_type table. Execute the following SQL:
select distinct(type) from prod_type
Also read the posting FAQ: https://stackoverflow.com/faq
Modify it like this:
Public Function get_type() As String
'get type
If IsPostBack = False Then
ds.Clear() //new
ddtype.Items.Clear() //new
da = New OleDbDataAdapter("select (type) from prod_type", con)
da.Fill(ds, "prod_type")
ddtype.DataSource = ds
ddtype.DataTextField = "type"
ddtype.DataValueField = "type"
ddtype.DataBind()
da.Dispose()
ds.Dispose()
con.Close()
End If
And if you still have duplicate entries it should be because you have duplicates in the database.
There are two cases where the values would be duplicated in the DropDownList here:
There are duplicated values in the database.
You are calling the function multiple times at the first loading of the page.
You can solve the first case by using DISTINCT in your select statement:
SELECT DISTINCT type FROM prod_type
You can solve the second by setting the value of the TableAdapter.ClearBeforeFill property to true.
Related
I have an asp.net listbox on my page, that I want to sort.
E.g: listbox(lstChooseFields)
MY VB code:
Private Sub LoadColumns()
If drpScreen.SelectedIndex > -1 Then
Dim daLookup As New LookupTableAdapters.LookupTableAdapter
Dim dtLookup As New System.Data.DataTable
dtLookup = daLookup.GetNestedControlValues("EM", "ExcelExport.aspx", "drpScreen", "drpScreen", drpScreen.SelectedValue)
lstChooseFields.DataSource = dtLookup
lstChooseFields.DataValueField = "LKP_ControlValue"
lstChooseFields.DataTextField = "LKP_ControlText"
lstChooseFields.DataBind()
'Dispose
daLookup.Dispose()
End If
End Sub
I have done some searching and found something like 'dtLookup.DefaultView.Sort = "LKP_ControlText" that I can use but it does not work. I don't want to sort in my database only on this page, this listbox (lstChooseFields).
So if you want to sort for the datatable then you have tried dtLookup.DefaultView.Sort = "LKP_ControlText" but you have missed out one piece of word there dtLookup.DefaultView.Sort = "LKP_ControlText asc". This generally works if LKP_ControlText is a column name in the datatable
You must use the word ascthere. which i couldnt find in your question.
After getting the dataTable sorted you can copy the same structure to another datatable if u want by using
Dim dtDuplicateLookup As New DataTable()
dtDuplicateLookup = dtLookup.DefaultView.ToTable(True)
and then access dtDuplicateLookup for further use if you want to retain the previous datatable as it is.
Use the .sorted property for the list box as shown here.
lstChooseFields.Sorted = True
UPDATE: your method was right but just tune it this way. I think you missed the DESC part. The second expression tells it how to sort the dataview.
Dim dataView As New DataView(table)
dataView.Sort = " column_name DESC" //DESC or ASC as per requirement
Dim dataTable AS DataTable = dataView.ToTable()
Else try this. After sorting a defaultview, generally you have to loopback through it
foreach(DataRowView r in table.DefaultView)
{
//... here you get the rows in sorted order
//insert the listbox items one by one here using listbox.add or listbox.insert commands
}
I have an ASP.NET page written in VB.NET that gets the items into a GridView by using a SELECT statement with INNER JOIN and also allows you to add an item to the invoice.
INNER JOIN that gets data from items and project_items.
SELECT Items.item_id, Items.item_name, Items.item_cost, project_items.item_quantity
FROM Items
INNER JOIN project_items
ON items.item_id = project_items.item_id
WHERE project_items.project_id = #parameter
#parameter is Session("ProjectID")
(There is a foreign key project_items.item_id -> items.item_id.)
I have an trying to use an SQL statement in VB.NET to try and INSERT into two tables simultaneously. What I tried is I tried to get the item_id of the last record created and insert into another table (project_items) by using that data. However, data is only being entered into the first table.
Any idea what I can do?
This is the code:
Protected Sub btnAddItem_Click(sender As Object, e As EventArgs) Handles btnAddItem.Click
Dim conn As New SqlConnection("Data Source=BRIAN-PC\SQLEXPRESS;Initial Catalog=master_db;Integrated Security=True")
Dim addItemComm As String = "SELECT item_id FROM project_items WHERE project_id=#ProjectID"
Dim user_id_select As New Integer
Dim addItemSQL As New SqlCommand
conn.Open()
addItemSQL = New SqlCommand(addItemComm, conn)
addItemSQL.Parameters.AddWithValue("#ProjectID", Convert.ToInt32(Session("ProjectID")))
Dim datareader As SqlDataReader = addItemSQL.ExecuteReader()
datareader.Close()
conn.Close()
Dim AddNewItemComm As String = "INSERT INTO Items (item_name, item_cost, item_code) VALUES (#ItemName, #ItemCost, #ItemCode); SELECT SCOPE_IDENTITY()"
Dim AddNewItem2Comm As String = "INSERT INTO project_items (item_id, project_id, item_quantity) VALUES (#ItemID, #ProjectID, #ItemQuantity) "
Dim AddNewItemSQL As New SqlCommand
conn.Open()
AddNewItemSQL = New SqlCommand(AddNewItemComm, conn)
AddNewItemSQL.Parameters.AddWithValue("#ItemName", txtItemName.Text.Trim)
AddNewItemSQL.Parameters.AddWithValue("#ItemCost", Convert.ToInt32(txtItemCost.Text))
AddNewItemSQL.Parameters.AddWithValue("#ItemCode", txtItemCost.Text.ToString.ToUpper)
Dim ItemId As Integer
ItemId = AddNewItemSQL.ExecuteScalar()
AddNewItemSQL.ExecuteNonQuery()
conn.Close()
conn.Open()
AddNewItemSQL = New SqlCommand(AddNewItem2Comm, conn)
AddNewItemSQL.Parameters.AddWithValue("#ItemID", ItemId)
AddNewItemSQL.Parameters.AddWithValue("#ProjectID", Convert.ToInt32(Session("ProjectID")))
AddNewItemSQL.Parameters.AddWithValue("#ItemQuantity", Convert.ToInt32(txtItemQuantity.Text))
AddNewItemSQL.ExecuteNonQuery()
conn.Close()
End Sub
Why are you doing this in multiple statements in the first place? Why not:
INSERT dbo.Items (item_name, item_cost, item_code)
OUTPUT inserted.ItemID, #ProjectID, #ItemQuantity
INTO dbo.project_items(item_id, project_id, item_quantity)
VALUES (#ItemName, #ItemCost, #ItemCode);
Now you only have to call one ExecuteNonQuery() and your app doesn't have to care about the actually SCOPE_IDENTITY() value generated. (You can still retrieve SCOPE_IDENTITY() if you want, of course, using ExecuteScalar - but as Nenad rightly points out, pick one instead of calling both.)
Since we now know that there is an explicit foreign key here, we can still reduce your C# code to one call even if we can't use the OUTPUT clause.
DECLARE #i INT;
INSERT dbo.Items (item_name, item_cost, item_code)
SELECT #ItemName, #ItemCost, #ItemCode;
SELECT #i = SCOPE_IDENTITY();
INSERT dbo.project_items(item_id, project_id, item_quantity)
SELECT #i, #ProjectID, #ItemQuantity
SELECT #i; -- if necessary
Would be even cleaner to put this into a stored procedure.
ItemId = AddNewItemSQL.ExecuteScalar()
AddNewItemSQL.ExecuteNonQuery()
These two rows next to each other will execute the command twice. You should remove the second one - ExecuteNonQuery. This will have your data inserted twice in the Items - two same rows but with different IDs.
Since you only retrieve ItemID from the first row, that one should be inserted in project_items, but the other one that was last inserted in items will have no matching row.
Also - complete section from beginning of button click method up before Dim AddNewItemComm As String - where you open and close DataReader and do nothing with it seems completely unnecessary.
What I want to do is to look for the text that is entered on textbox4 assigned to Valor and display if found, the below code is working but I want to use parametized queries (security reasons) and I don't know how to modify my existing code to get it done. (eg, 123-A)
I will look for "123-A" but in the current code I got an error of "invalid column A", the SQL column that I will be looking "123-A" is "ID_LALTest"
Try
' *--------search by Unique ID-------*
Dim CON As New SqlConnection
Dim DA As New SqlDataAdapter
Dim DS As New DataSet
Dim SQL As String
Dim Valor As String
Valor = TextBox4_SearchData_LALTest.Text
CON.ConnectionString = "not displayed"
CON.Open()
SQL = "SELECT ID_LALTest, LALTest_SeqRef_CH, LALTest_SeqRef_Year FROM LALTest WHERE ID_LALTest=#Valor"
DA = New SqlDataAdapter(SQL, CON)
DA.SelectCommand.Parameters.AddWithValue("#Valor", Valor)
DA.SelectCommand.ExecuteNonQuery()
DA.Fill(DS, 0)
If DS.Tables(0).Rows.Count > 0 Then
' *--------Found, Display Data Grid-------*
Label2_SearchData_LALTest.Visible = False
GridView2_SearchData_LALTest.Visible = True
GridView3_SearchData_LALTest.Visible = True
GridView1_SearchData_LALTest.Visible = False
Else
Label2_SearchData_LALTest.Text = "Record Not Found"
Label2_SearchData_LALTest.Visible = True
GridView2_SearchData_LALTest.Visible = False
GridView3_SearchData_LALTest.Visible = False
GridView1_SearchData_LALTest.Visible = False
End If
con.dispose()
Catch ex As Exception
MsgBox(Err.Description)
End Try
Yup, you are wide-open for sql-injection. Depending on different databases (you just have SQL, but is that SQL-Server, MySQL, an Access/SQL database, etc).
Anyhow, it's not too far off from what you have. Not specializing in VB, I'll give you some pseudo-code for it...
Change your query, and put in a "place-holder" for the "variable" you want to apply from the input... Ex:
"select (your fields) from (yourtable) where ID_LALTest = #parmValor"
Then, add the parameters to your sql command created for your data adapter... something like...
DA.SelectCommand.Parameters.Add( "#parmValor", theInputFromYourVariable );
Now, if you have multiple conditions you want to apply, just keep adding "#someParm" value and add the parameters IN THE SAME ORDER as they exist in the query... I've heard from others in the past, that just the ordinal sequence of parameters not matching the query can/does cause problems... such as data type expectations too.
I'm trying to retrieve values using VB.NET from a SQL database. How do I use SqlDataSource.Select()? Is there a way to move the value to a variable that I can use for other things?
I know its kind of scattered and vague but that is the best I can do. I basically need to set a labels text to a value in a table.
This puts the result query in to a DataTable.
DataView view = (DataView)dataSource.Select(new DataSourceSelectArguments());
DataTable groupsTable = view.ToTable();
String value;
foreach (DataRow dr in dt.Rows)
{
// Do something here IE grab the value of the first column
value = dr[0];
}
Repying to last question in comment:
YourTable.Rows(index)(index)
YourTable.Rows(index)("columnname")
I was getting crazy trying to do this simple operation:
retrieving data from sqldatasource and put it into variables that I can manipulate.
At the end, Here the working behind code to do this for VB.NET:
Dim DV As New DataView()
Dim DataTable As New DataTable()
Dim SqlDataSource1 As New SqlDataSource()
Dim VALUE As String
SqlDataSource1.ID = "SqlDataSource1"
Me.Page.Controls.Add(SqlDataSource1)
SqlDataSource1.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings("Connection_name").ConnectionString
SqlDataSource1.SelectCommand = "SELECT * from Table"
DV = CType(SqlDataSource1.Select(DataSourceSelectArguments.Empty), DataView)
DataTable = DV.ToTable()
For Each riga As DataRow In DataTable.Rows
VALUE = riga("table_name").ToString
Next
the for each, in this case gets only the first value but you can get any value from datatable and put it into vector, or other strings, so you can control data coming from sqldatasource.
ENJOY
I used to use datasets instead of sqldatareaders and I used to be able to do something like this
If dataset.tables(0).Rows(0)(1).ToString()) = "N" Then
lbl.Text = dataset.tables(0).Rows(0)(2).ToString())
Else
'Do Nothing
End If
This obviously doesn't work with sqldatareaders.
I have code to see if the SQLDatareader has any rows but was wondering if there was a way to get the value of each row
I'm guessing this is possible and i've had a look around but can't seem to find anything
Dim conn As SqlConnection = New SqlConnection("server='h'; user id='w'; password='w'; database='w'; pooling='false'")
conn.Open()
Dim query As New SqlCommand("DECLARE #investor varchar(10), #sql varchar(1000) Select #investor = 69836 select #sql = 'SELECT * FROM OPENQUERY(db,''SELECT * FROM table WHERE investor = ''''' + #investor + ''''''')' EXEC(#sql)", conn)
Dim oDR As SqlDataReader = query.ExecuteReader()
If oDR.HasRows or dataset.tables(0).Rows(0)(1).ToString()) = "N" Then
lbl.Text = dataset.tables(0).Rows(0)(2).ToString())
Else
'Do Nothing
End If
That is the code I have at the moment which obviously doesn't work
Any ideas?
Thanks
When you use the data reader you have to step through each row yourself. Using HasRows is a good start, for it will tell you if the returned result set is empty.
To iterate through the result set you should use the Read() method. It will return true if you are at a row and false when you have moved past the last row.
My Vb is poor so I will give you an example in C# instead:
if (oDR.HasRows && oDR.Read())
{
if (oDR.GetString(0) == "N")
{
lbl.Text = oDr.GetString(1);
}
}
Here I first check that we have a result set with data and then try to move to the first row. If this succeeds I then read the string value of the first column and compare it to "N". If the value is equal to "N" I set the Text property of the lbl variable to the string value of the second column.
This should be equivalent to your algorithm with the dataset. I recommend that you read the MSDN documentation for the SqlDataReader. It is quite good and the example code is useful.