Is there a way to use DateTimePicker as your searching device for ListView?
I don't know how to use DateTimePicker as my search engine...
HERE IS THE CODES FOR MY SEARCH:
Dim conn As SqlConnection
Dim cmd As SqlCommand
Dim da As SqlDataAdapter
Dim ds As DataSet
Dim itemcoll(100) As String
Me.ListView1.View = View.Details
Me.ListView1.GridLines = True
ListView1.Items.Clear()
conn = New SqlConnection("Data Source=#####;Initial Catalog=#####;Persist Security Info=True;User ID=#####;Password=#####")
Dim strQ As String = String.Empty
strQ = "SELECT ControlNo,EmpNo,CheckOutDate,CheckOutTime,TaxiNo,PlateNo,Model,Make FROM dbo.ChkInOut WHERE ControlNo ='" + txtsearch.Text + "'"
cmd = New SqlCommand(strQ, conn)
da = New SqlDataAdapter(cmd)
ds = New DataSet
da.Fill(ds, "Table")
Dim i As Integer = 0
Dim j As Integer = 0
For i = 0 To ds.Tables(0).Rows.Count - 1
For j = 0 To ds.Tables(0).Columns.Count - 1
itemcoll(j) = ds.Tables(0).Rows(i)(j).ToString()
Next
Dim lvi As New ListViewItem(itemcoll)
Me.ListView1.Items.Add(lvi)
Next
There are few problems with your code as is, so let's take them one at a time
SqlCommand inherits from DbCommand, which implements the IDisposable interface.
The primary use of this interface is to release unmanaged resources.
The best way do that is with the Using keyword. For a code example of that, take a look at the sample code at the bottom of this page.
Same goes for SqlConnection, wrap it in a Using statement.
Don't concatenate strings together to make SQL queries, this opens your application up to SQL Injection attacks. There are examples of how to create parameterized queries here and here (unfortunately I didn't see a good example on MSDN).
In your case, the query will look like this:
strQ = "SELECT ControlNo, ..<rest of columns>.. ,Model,Make " & _
"FROM dbo.ChkInOut " & _
"WHERE ControlNo = #controlNo"
cmd = New SqlCommand(strQ, conn)
cmd.Parameters.AddWidthValue("#controlNo", txtsearch.Text);
... rest of code here ...
To query by a user specified date, you need to first get the date from the DateTimePicker.Value property. Then construct a query (like in the example above) and pass a parameter with the selected date. You may find this question abou SQL Server dates helpful.
Related
This is my code example to run parameterized query in VB.NET:
Dim sqlconn As New SqlConnection(connectionString)
sqlconn.Open()
Dim cmd As New SqlCommand
cmd.CommandText = "Select * from TAble1 Where SkuCode in (#SKU)"
cmd.Connection = sqlconn
Dim parm As New SqlParameter
parm.Value ="1" 'This is working
parm.ParameterName = "#SKU"
cmd.Parameters.Add(parm)
Dim ds As New DataSet
Dim sqlDa As New SqlDataAdapter(cmd)
sqlDa.Fill(ds)
Dim dt As DataTable
dt = ds.Tables(0)
If dt.Rows.Count > 0 Then
MsgBox("Done")
Else
MsgBox("Not done.")
End If
If I run this example in VB.NET this returns the result successfully.
But there is an issue while trying to get results with multiple in records... this is not working.
Please check and suggest the change we have to do to run in query with parameters.
'parm.Value = "N'1', N'2'" 'this does not work.
'parm.Value = "'1','2'" 'this does not work.
I have tried these parameter value but it does not work.
SQL parameters are scalar and only accept a single value. You can use the sqldbtype.Structured though it gets a bit complicated.
I've found that if you need to pass in a set of parameters for an IN where the number of parameters is dynamics, the most effective way (unfortunately) is:
String interpolation/concatenation without parameters
Loop to build out the parameters and add them to your sqlcommand
LINQ to build out the parameters and add them to your sqlcommand
I've provided an example of the linq option below.
Dim sqlParams As Dictionary(Of String, Integer) = integers.ToDictionary(Function(i) $"#ParamValue{i}", Function(i) i)
Dim ds As New DataSet
Dim dt As DataTable
Using db as new SqlConnection(conn)
conn.open()
Using cmd As New SqlCommand($"SELECT * FROM Table1 WHERE SkuCode IN (-1, {String.Join(", ", sqlParams.Select(Function(f) f.Key))}", db)
cmd.Parameters.AddRange(sqlParams.Select(Function(f) New SqlParameter(f.Key, SqlDbType.BigInt).Value = f.Value).ToArray())
Dim sqlDa As New SqlDataAdapter(cmd)
sqlDa.Fill(ds)
dt = ds.Tables(0)
End Using
End Using
MsgBox(If(dt.Rows.Count > 0, "Done", "Not done"))
I am a beginner and really need help. I want to display data from the database and assign the values to the textboxes and a combobox on a form, but I get this error
Incorrect syntax near "="
It appears is on this line
myreader = cmd.ExecuteReader
Please - any help?
Sub ref()
Dim conn As New SqlConnection
conn.ConnectionString = ("Data Source=.;Initial Catalog=UEW_ADMISSION_CHEAKER;Integrated Security=True")
conn.Open()
Dim strsql As String
strsql = "SELECT ProgName,MaleCuteOff,FemaleCutOff from CutOff_Point where ProgName=" + cmbCourse.SelectedItem + ""
Dim cmd As New SqlCommand(strsql, conn)
Dim myreader As SqlDataReader
myreader = cmd.ExecuteReader
myreader.Read()
txtFemale.Text = myreader("FemaleCutOff")
txtMale.Text = myreader("MaleCuteOff")
conn.Close()
End Sub
You should always use SQL parameters to pass parameters to SQL - it avoids embarrasing problems like single quotes breaking the query and deliberate SQL injection attacks.
It's probably best to make sure that there is a selected value before trying to use it.
Some things, e.g. database connections, use "unmanaged resources" and it is necessary to use the Dispose() method to make sure that things are cleaned up afterwards. The Using statement is a convenient way to get the computer to take care of that for you.
I didn't see a need for the query to return the value that was passed to it (ProgName).
You will need to adjust the .SqlDbType and .Size to match the database column.
Option Strict On
' ... other code
Sub Ref()
If cmbCourse.SelectedIndex >= 0 Then
Dim sql As String = "SELECT MaleCuteOff, FemaleCutOff FROM CutOff_Point WHERE ProgName = #ProgName"
Dim connStr = "Data Source=.\;Initial Catalog=UEW_ADMISSION_CHEAKER;Integrated Security=True"
Using conn As New SqlConnection(connStr),
cmd As New SqlCommand(sql, conn)
cmd.Parameters.Add(New SqlParameter With {.ParameterName = "#ProgName", .SqlDbType = SqlDbType.VarChar, .Size = 99, .Value = cmbCourse.SelectedItem})
conn.Open()
Dim rdr As SqlDataReader = cmd.ExecuteReader()
If rdr.HasRows Then
rdr.Read()
txtFemale.Text = rdr.GetInt32(0).ToString()
txtMale.Text = rdr.GetInt32(1).ToString()
End If
End Using
End If
End Sub
P.S. Shouldn't UEW_ADMISSION_CHEAKER be UEW_ADMISSION_CHECKER? It's best to have things spelt correctly as it is easier to type them.
First of all this Block of Code is not OK. You could use :
Using....End Using Method.
SqlCommand.Parameters Property for security issues.
Connection Strings and Configuration Files for security issues.
Allow me to rewrite your Code using the above methods.
Private Sub RetrieveAndDisplayCutOff()
Dim sbMale As New StringBuilder
Dim sbFemale As New StringBuilder
Dim strsql As String =
"SELECT MaleCutOff,FemaleCutOff FROM CutOff_Point WHERE ProgName = #ComboItem"
Using conn As New SqlConnection("Data Source=.;Initial Catalog=UEW_ADMISSION_CHEAKER;Integrated Security=True"),
CMD As New SqlCommand(strsql, conn)
CMD.Parameters.Add("#ComboItem", SqlDbType.VarChar).Value = ComboBox1.SelectedItem.ToString
conn.Open()
Using MyReader As SqlDataReader = CMD.ExecuteReader
While MyReader.Read 'Returns False if no more rows
'OP mentioned in comments that these fields were int
sbMale.AppendLine(MyReader.GetInt32(0).ToString)
sbFemale.AppendLine(MyReader.GetInt32(1).ToString)
End While
End Using
End Using
txtMale.Text = sbMale.ToString
txtFemale.Text = sbFemale.ToString
End Sub
I am trying to take all the items from a list box and save them into separated fields into a SQL Server database. The user pushes a save button and I would like for all of the items in the list box to be separated into their appropriate fields and saved into said fields in the SQL Server database. The items start out separated in a DGVgrid and are combined when the enter the List box. What is the best way to go about this? The SQL Server database has the same columns and the DGVgrid.
I am using VB in Visual Studio and a SQL Server database that I have created on my machine. Any help would be greatly appreciated. I have been stuck on this for a bit and I'm not sure where to go from here.
I think that the problem may be the List boxes because I have been able to save to my SQL Server database when the data comes from Text boxes, but I do not want to get rid of the List boxes. I have tried changes the List boxes out with DGVgridview boxes, but this did not work. I could not get the items to neatly go into the columns that they needed to. Would I be better of just trying to save the data into a Text file?
Public Function InStrRev(StringCheck As String, StringMatch As String, Optional Start As Integer = -1, Optional Compare As CompareMethod = Microsoft.VisualBasic.CompareMethod.Binary) As Integer
End Function
Public Function InStr(Start As Integer, String1 As String, String2 As String, Optional Compare As CompareMethod = Microsoft.VisualBasic.CompareMethod.Binary) As Integer
End Function
Public Function Mid(Str As String, Start As Integer, Length As Integer) As String
End Function
Static IntStart As Integer
Dim Backpack1 = BP1ListBox.ToString()
Dim Backpack2 = BP2ListBox.ToString()
Dim user As String = ReturningUser.UserNametxt.Text
Dim con As SqlConnection
Dim deletecmd As SqlCommand
Dim objcmd As SqlCommand
Dim deletereader As SqlDataReader
Dim reader As SqlDataReader
Dim BackpackName As String
Dim item As String
Dim weightposition As Integer
Dim weight As String
Dim username As String = CStr(ReturningUser.UserNametxt.Text)
Dim delete As String = "Delete From UserBackpackItems where UserName = '" & username & "'"
Dim stmt As String = "Insert Into UserBackpackItems(UserName, BackpackName, Item, Weight,) Values('" & username & "', '" & BackpackName & "', '" & ItemNametxt.Text & "', '" & ItemWeighttxt.Text & "')"
con = New SqlConnection("Data Source=DESKTOP-AUS1VBC\SQLEXPRESS;Initial Catalog=BackpackDatabase;Integrated Security=True")
con.Open()
'delete previous save
deletecmd = New SqlCommand(delete, con)
deletereader = deletecmd.ExecuteReader()
'create a new save
For Counter = IntStart To BP1ListBox.Items.Count - 1
Dim ListItems As String = BP1ListBox.Items.ToString
item = Mid(ListItems(Counter), 1, InStr(1, ListItems(Counter), " ", CompareMethod.Text))
weightposition = InStrRev(ListItems(Counter), " ", CompareMethod.Text)
weight = Mid(ListItems(Counter), weightposition, Length:=BP1ListBox.Items(Counter))
objcmd = New System.Data.SqlClient.SqlCommand(stmt, con)
reader = objcmd.ExecuteReader()
Next
I'm updating SQL Server from VB.NET and keep getting the 'Query Timeout Error', I have lot's of sub routines that I run in sequence that look like the following:
Public Shared Sub Update_DailyRatings()
Dim stallStats As String = ""
Dim win As Integer = 0
Dim mSplit As Array
Dim cn As OleDbConnection = New OleDbConnection(MainForm.connectStringPublic)
cn.Open()
Dim selectString As String = "Select * FROM DailyRatings"
Dim cmd As OleDbCommand = New OleDbCommand(selectString, cn)
Dim reader As OleDbDataReader = cmd.ExecuteReader()
While (reader.Read())
stallStats = Get_Stall_Stats(reader("Track").ToString, CInt(reader("Stall")), CDbl(reader("Distance")))
If stallStats = "" Then
MainForm.NonQuery("UPDATE DailyRatings SET StallWin = 999 WHERE Horse = '" & reader("Horse").ToString & "'")
Else
mSplit = Split(stallStats, ",")
win = mSplit(0)
MainForm.NonQuery("UPDATE DailyRatings SET StallWin = " & win & " WHERE Horse = '" & reader("Horse").ToString & "'")
End If
End While
reader.Close()
cn.Close()
End Sub
The NonQuery sub looks like this:
Public Sub NonQuery(ByVal SQL As String)
Dim query As String = SQL
Try
Dim cn3 As OleDbConnection = New OleDbConnection(connectStringPublic)
cn3.Open()
Dim cmd As OleDbCommand = New OleDbCommand(query, cn3)
cmd.CommandTimeout = 90
cmd.ExecuteNonQuery()
cn3.Close()
cn3.Dispose()
cmd.Dispose()
OleDbConnection.ReleaseObjectPool()
Catch e As System.Exception
Clipboard.SetText(query)
MsgBox(e.Message)
Finally
End Try
End Sub
As you can see I've been trying ideas to fix this that I found in other threads such as extending the timeout and using the Dispose() and ReleaseObjectPool() methods but it hasn't worked, I still get query timeout error at least once when running all my subs in sequence, it's not always the same sub either.
I recently migrated from Access, this never used to happen with Access.
If you are dealing with Sql Server why are you using OleDb? I guessed that is was really access.
While your DataReader is open, your connection remains open. With the amount of processing you have going on, it is no wonder that your connection is timing out.
To begin, connections and several other database objects need to be not only closed but disposed. They may contain unmanaged resources which are released in the .Dispose method. If you are using an object that exposes a .Dispose method use Using...End Using blocks. This will take care of this problem even if there is an error.
Actually you have 2 distinct operations going on. First you are retrieving DailyRatings and then you are updating DailyRatings base on the data retrieved. So we fill a Datatable with the first chunk of data and pass it off to the second operation. Our first connection is closed and disposed.
In operation 2 we create our connection and command objects just as before except now our command has parameters. The pattern of the command is identical for every .Execute, only the values of the parameters change. This pattern allows the database, at least in Sql Sever, to cache a plan for the query and improve performance.
Public Shared Function GetDailyRatings() As DataTable
Dim dt As New DataTable
Using cn As New OleDbConnection(MainForm.connectStringPublic),
cmd As New OleDbCommand("Select * FROM DailyRatings", cn)
cn.Open()
dt.Load(cmd.ExecuteReader)
End Using
Return dt
End Function
Public Sub UpdateDailyRatings()
Dim dt = GetDailyRatings()
Using cn As New OleDbConnection(connectStringPublic),
cmd As New OleDbCommand("UPDATE DailyRatings SET StallWin = #Stall WHERE Horse = #Horse")
cmd.Parameters.Add("#Stall", OleDbType.Integer)
cmd.Parameters.Add("#Horse", OleDbType.VarChar)
cn.Open()
For Each row As DataRow In dt.Rows
cmd.Parameters("#Horse").Value = row("Horse").ToString
Dim stallStats As String = Get_Stall_Stats(row("Track").ToString, CInt(row("Stall")), CDbl(row("Distance")))
If stallStats = "" Then
cmd.Parameters("#Stall").Value = 999
Else
cmd.Parameters("#Stall").Value = CInt(stallStats.Split(","c)(0))
End If
cmd.ExecuteNonQuery()
Next
End Using
End Sub
Private Function GetStallStats(Track As String, Stall As Integer, Distance As Double) As String
Dim s As String
'Your code here
Return s
End Function
Note: OleDb does not pay attention to parameters names. It is the order that they appear in the query statement must match the order that they are added to the Parameters collection.
It's possible that OleDbDataReader is locking your table or connection as it get the data with busy connection. You can store the data in a DataTable by using OleDbDataAdapter and loop through it to run your updates. Below is the snippet how your code would look like:
Dim cmd As OleDbCommand = New OleDbCommand(selectString, cn)
Dim adapter As OleDbDataAdapter = New OleDbDataAdapter(cmd)
Dim dt As New DataTable()
adapter.Fill(dt)
For Each reader As DataRow In dt.Rows
stallStats = Get_Stall_Stats(reader("Track").ToString, CInt(reader("Stall")), CDbl(reader("Distance")))
If stallStats = "" Then
MainForm.NonQuery("UPDATE DailyRatings SET StallWin = 999 WHERE Horse = '" & reader("Horse").ToString & "'")
Else
mSplit = Split(stallStats, ",")
win = mSplit(0)
MainForm.NonQuery("UPDATE DailyRatings SET StallWin = " & win & " WHERE Horse = '" & reader("Horse").ToString & "'")
End If
Next
cn.Close()
I am attempting to pull values from an SQL Server table from VB.NET.
On VB Form 1, the number from NoTable, Row 1, is pulled successfully, and Label1 is updated with the value.
Dim command As SqlCommand
Dim query As String = "SELECT Number FROM NoTable"
command = New SqlCommand(query, con)
con.Open()
Dim datareader As SqlDataReader = cmd.ExecuteReader()
If datareader.Read() Then
Label1.Text = datareader.GetValue(0)
End If
datareader.Close()
On VB Form 2 I am attempting to pull the value from the second row, using:
Dim query As String = "SELECT Number FROM NoTable"
command = New SqlCommand(query, con)
con.Open()
Dim datareader As SqlDataReader = cmd.ExecuteReader()
If datareader.Read() Then
Label1.Text = datareader.GetValue(1)
End If
datareader.Close()
However, this does not work, and the label is not updated with the value from the second row.
An unhandled exception of type 'System.IndexOutOfRangeException' occurred in System.Data.dll
Additional information: Index was outside the bounds of the array."
How would I go about fixing this, so that on Form 2, the value from Row 2 is pulled, and so forth?
Thank you.
Firstly, you only get one column back from the reader, but you are indexing the columns with that 0 or 1. So you should always pass 0 to GetValue.
To index the row instead, try this. Assign a form number to each form (first line in my example) and use that to determine which record to assign to the Label. There is probably a more efficient way to do this (not returning all the records before it) but this solution should fit in your environment.
' in form # 1
Dim formNumber = 1
Dim command As SqlCommand
Dim query As String = "SELECT Number FROM NoTable"
command = New SqlCommand(query, con)
con.Open()
Dim datareader As SqlDataReader = cmd.ExecuteReader()
Dim index = 0
While index < formNumber
If datareader.Read() AndAlso index = formNumber Then
Label1.Text = datareader.GetValue(0)
End If
index += 1
End While
datareader.Close()
See https://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqldatareader.getvalue(v=vs.110).aspx
And another similar question in c# Access a specific row in DataReader
Another way is to just return the row you need in the first place, without iterating over the records on the client side. Assuming there is another column with an index which is in the same order as the row you want to return, called "ID"
' in form # 1
Dim formNumber = 1
Dim command As SqlCommand
Dim query As String =
"SELECT Number FROM " & _
" (SELECT Number, Row_Number() OVER (ORDER BY ID) AS RowNumber " & _
" FROM NoTable) AS Results " & _
" WHERE Results.RowNumber = " & formNumber.ToString()
command = New SqlCommand(query, con)
con.Open()
Dim datareader As SqlDataReader = cmd.ExecuteReader()
Label1.Text = datareader.GetValue(0)
datareader.Close()
See https://msdn.microsoft.com/en-us/library/ms186734.aspx
GetValue(1) does not exist, as this would refer to a second column in the select statement. You are only asking for [Number] which would be datareader.GetValue(0)