I know there are some threads about this topic, but for some reason nothing of these things given there didn't work for me. So that is my code:
Dim strAccSQL As String = "SELECT nUserNo FROM dbo.tUser WHERE sUserID='" & AccountID.Text & "';"
Dim catCMDAcc As SqlCommand = New SqlCommand(strAccSQL, AccCon)
Dim myAccountReader As SqlDataReader = catCMDAcc.ExecuteReader()
While myAccountReader.Read
AccountNo.Text = myAccountReader(0)
End While
myAccountReader.Close()
Con.Close()
Con.Open()
Dim strSQL2 As String
Dim catCMD As SqlCommand = New SqlCommand(strSQL2, Con)
Dim myReader As SqlDataReader = catCMD.ExecuteReader()
InfoTextBox.Text &= Environment.NewLine & Now & " Account: " & AccountID.Text & " Found"
CharacterName.Properties.Items.Clear()
While myReader.Read()
CharacterName.Properties.Items.Add(myReader(0))
End While
myReader.Close()
AccCon.Close()
Con.Close()
Anyone got an idea for my problem?
As the errormessage states, your CommandText is empty string here (strSQL2):
Dim strSQL2 As String
Dim catCMD As SqlCommand = New SqlCommand(strSQL2, Con)
Dim myReader As SqlDataReader = catCMD.ExecuteReader()
You cannot execute an empty sql-clause.
Related
Dim con As New OleDb.OleDbConnection
Dim str As String = "Provider=Microsoft.ACE.OLEDB.12.0; Data Source=..\VisitorPass.accdb"
con = New OleDbConnection(str)
Dim sql As String = "insert into Visitor(Name,Password)values ('" & txtName.Text & "','" & txtPassword.Text & "')"
Dim cmd As OleDbCommand
con.Open()
cmd = New OleDbCommand(sql, con)
cmd.ExecuteNonQuery()
MsgBox("Account is Registered")
Try enclosing the field password in brackets.
insert into Visitor(Name,[Password])values ..
This should do the trick when using MS Access.
I have this code i wrote to find out if a record exists in data base. It works well when record is found. If it isn't, it brings up an error. I would like the error to be caught in a messagebox that states "record not found" instead.
Dim findprinc As String = TextBox1.Text.Substring(0, 16)
MsgBox(findprinc)
sql = "Select RealID from Dets where ID like '%" & findprinc & "%'"
MsgBox(sql)
Dim conn As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Persist Security Info=false; Data Source=..\new.mdb")
conn.Open()
Dim cmd As New OleDbCommand(sql, conn)
Dim numeri As OleDbDataReader = cmd.ExecuteReader
numeri.Read()
Dim findprinc As String = TextBox1.Text.Substring(0, 16)
MsgBox(findprinc)
Sql = "Select RealID from Dets where ID like '%" & findprinc & "%'"
MsgBox(Sql)
Dim conn As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; Persist Security Info=false; Data Source=..\new.mdb")
conn.Open()
Dim cmd As New OleDbCommand(Sql, conn)
Dim numeri As OleDbDataReader = cmd.ExecuteReader
Dim recordFound As Boolean = False
While numeri.Read
recordFound = True
End While
If recordFound = False Then
MsgBox("Record Not Found")
End If
I am trying to check if value "IAV-1419" exist in second column (ColName) in database named PROMGL.DBF.
I get this error : No value give for one or more required parameters
Dim con As New OleDbConnection
Dim cmd As New OleDbCommand
Dim FilePath As String = "C:\"
Dim DBF_File As String = "PROMGL"
Dim ColName As String = "[NALOG,C,8]"
con.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & FilePath & _
" ;Extended Properties=dBASE IV"
cmd = New OleDbCommand("SELECT * FROM PROMGL WHERE [NALOG,C,8] = #NAL")
cmd.Connection = con
con.Open()
cmd.Parameters.AddWithValue("#NAL", "IAV-1419")
Using reader As OleDbDataReader = cmd.ExecuteReader()
If reader.HasRows Then
con.Close()
Label6.Text = "EXIST"
TextBox1.Text = ""
TextBox1.Focus()
Else
Label6.Text = "DOESN'T EXIST"
End If
End Using
I am stuck here, if anyone could please check this code for me.
are you sure that your connectionstring is correct????
Data Source=" & FilePath &
how connection string know the database where it point only to "C:\" i think is missing database name
Another personal suggestion make your code more simple to read in example :
Dim FilePath As String = "C:\"
Dim DBF_File As String = "PROMGL"
Dim ColName As String = "[NALOG,C,8]"
Using con As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & FilePath & _
" ;Extended Properties=dBASE IV")
con.Open()
Using cmd As New OleDbCommand("SELECT * FROM PROMGL WHERE [NALOG,C,8] = #NAL", con
cmd.Parameters.AddWithValue("#NAL", "IAV-1419")
Using reader As OleDbDataReader = cmd.ExecuteReader()
If reader.HasRows Then
Label6.Text = "EXIST"
TextBox1.Text = ""
TextBox1.Focus()
Else
Label6.Text = "DOESN'T EXIST"
End If
End Using
End Using
End Using
I am creating a pageant scoring system,
I have this functions for populating my datagridview's first column using query:
Public Sub searchContestant()
If comboCategory.SelectedIndex <> 0 Then
Dim id As Integer = Login.JudgeBindingSource1.Current("Cont_id")
Dim critID As Integer = Convert.ToInt32(lblID.Text)
'search the contest record by the contest_id
Dim con As New SqlConnection
Dim reader As SqlDataReader
Dim reader2 As SqlDataReader
Dim dt = New DataTable()
Dim nc As New DataGridViewTextBoxColumn
DataGridView1.Columns.Clear()
DataGridView1.Rows.Clear()
Try
con.ConnectionString = "Data Source=BROWNIE\SQLEXPRESS;Initial Catalog=PSS;Integrated Security=True"
Dim cmd As New SqlCommand("SELECT * from Criteria where Cat_id = '" & critID & "' ", con)
Dim cmd2 As New SqlCommand("SELECT * from Contestant where Cont_id = '" & id.ToString() & "' ", con)
con.Open()
' Execute Query
reader = cmd.ExecuteReader()
nc.Name = "Contestants"
nc.Width = 250
nc.ReadOnly = True
DataGridView1.Columns.Add(nc)
While reader.Read()
nc = New DataGridViewTextBoxColumn
nc.Name = "(" & reader.GetString(2) & "%)" & reader.GetString(1)
nc.HeaderText = "(" & reader.GetString(2) & "%)" & reader.GetString(1)
nc.Width = 150
DataGridView1.Columns.Add(nc)
End While
Catch ex As Exception
MessageBox.Show("Error while connecting to SQL Server." & ex.Message)
Finally
con.Close() 'Whether there is error or not. Close the connection. '
End Try
Try
'populate contestant rows
con.ConnectionString = "Data Source=BROWNIE\SQLEXPRESS;Initial Catalog=PSS;Integrated Security=True"
Dim cmd2 As New SqlCommand("SELECT * from Contestant where Cont_id = '" & id.ToString() & "' ", con)
con.Open()
reader2 = cmd2.ExecuteReader()
While reader2.Read()
nc = New DataGridViewTextBoxColumn
nc.Width = 100
DataGridView1.Rows.Add(reader2.GetString(2).ToString())
End While
Catch ex As Exception
MessageBox.Show("Error while connecting to SQL Server." & ex.Message)
Finally
con.Close() 'Whether there is error or not. Close the connection. '
End Try
End If
End Sub
And for succeeding columns :
Public Sub searchCriteria()
Dim con As New SqlConnection
Dim reader4 As SqlDataReader
Dim dt = New DataTable()
Dim nc As New DataGridViewTextBoxColumn
DataGridView1.Columns.Clear()
Try
'populate Criteria
con.ConnectionString = "Data Source=BROWNIE\SQLEXPRESS;Initial Catalog=PSS;Integrated Security=True"
Dim cmd As New SqlCommand("SELECT * from Criteria where Cat_id = '" & lblID.Text & "' ", con)
con.Open()
reader4 = cmd.ExecuteReader
While reader4.Read
nc = New DataGridViewTextBoxColumn
nc.Name = reader4.GetString(1).ToString & Chr(13) & reader4.GetString(2).ToString & "%"
nc.Width = 100
DataGridView1.Columns.Add(nc)
End While
Catch ex As Exception
MessageBox.Show("Error while connecting to SQL Server." & ex.Message)
Finally
con.Close() 'Whether there is error or not. Close the connection. '
End Try
End Sub
This is the output:
And everytime a judge login, I insert data into the system with this function:
Public Sub makeTransaction()
Dim con2 As New SqlConnection
'get the judge id upon logging in
Dim judgeID = Login.JudgeBindingSource1.Current("Judge_id")
'get the contest id of the judge
Me.JudgeTableAdapter.FillByJudgeID(Me.PSSDataSet.Judge, judgeID)
Dim JudgeContestid = Login.JudgeBindingSource1.Current("Cont_id")
Me.ContestantTableAdapter.FillByContestID(Me.PSSDataSet.Contestant, JudgeContestid)
'get the contestant id
Me.ContestTableAdapter.FillByContestID(Me.PSSDataSet.Contest, JudgeContestid)
Dim contestID As Integer = ContestBindingSource.Current("Cont_id")
'get the category of the contest
Me.CategoryTableAdapter.FillByContestID(Me.PSSDataSet.Category, Convert.ToInt32(contestID))
For Each Category As DataRow In Me.PSSDataSet.Category.Rows
Me.CriteriaTableAdapter.FillByCategoryID(Me.PSSDataSet.Criteria, Category("Cat_id"))
For Each Contestant As DataRow In Me.PSSDataSet.Contestant.Rows
For Each Criteria As DataRow In Me.PSSDataSet.Criteria.Rows
TransactionsTableAdapter.Insert(JudgeContestid, Contestant("Con_id"), Criteria("Cri_id"), 0)
Next
Next
Next
End Sub
Now my problem is, how can I populate the datagrid using the data recently made by MakeTransaction() function?
I am new to this and had this question. Can I use SQLDataReader instead of a Recordset. I want to achieve the following result in an SQLDataReader.
Dim dbConn As New ADODB.Connection
Dim rs As New ADODB.Recordset
Dim sqlstr As String = "SELECT Name,Status FROM table1 WHERE id=" + item_id.Value.ToString
rs.Open(SQL, dbConn)
While Not rs.EOF
txtName.Text = rs.Fields.Item("Name").Value
ddlstatus.SelectedIndex = 1
rs.MoveNext()
End While
rs.Close()
rs = Nothing
dbConn.Close()
dbConn = Nothing
Can I replace recordset with SQLDataReader and if I can can you please show me the changes in code?
Its highly recommend that you use the using pattern:
Dim sConnection As String = "server=(local);uid=sa;pwd=PassWord;database=DatabaseName"
Using Con As New SqlConnection(sConnection)
Con.Open()
Using Com As New SqlCommand("Select * From tablename", Con)
Using RDR = Com.ExecuteReader()
If RDR.HasRows Then
Do While RDR.Read
txtName.Text = RDR.Item("Name").ToString()
Loop
End If
End Using
End Using
Con.Close()
End Using
You will have to swap out a few things, something similar to the following.
Here is an example, you will need to modify this to meet your goal, but this shows the difference.
I also recommend using a "Using" statement to manage the connection/reader. Also, a parameterized query.
Dim sConnection As String = "server=(local);uid=sa;pwd=PassWord;database=DatabaseName"
Dim objCommand As New SqlCommand
objCommand.CommandText = "Select * From tablename"
objCommand.Connection = New SqlConnection(sConnection)
objCommand.Connection.Open()
Dim objDataReader As SqlDataReader = objCommand.ExecuteReader()
If objDataReader.HasRows Then
Do While objDataReader.Read()
Console.WriteLine(" Your name is: " & Convert.ToString(objDataReader(0)))
Loop
Else
Console.WriteLine("No rows returned.")
End If
objDataReader.Close()
objCommand.Dispose()
Dim rdrDataReader As SqlClient.SqlDataReader
Dim cmdCommand As SqlClient.SqlCommand
Dim dtsData As New DataSet
Dim dtbTable As New DataTable
Dim i As Integer
Dim SQLStatement as String
msqlConnection.Open()
cmdCommand = New SqlClient.SqlCommand(SQLStatement, msqlConnection)
rdrDataReader = cmdCommand.ExecuteReader()
For i = 0 To (rdrDataReader.FieldCount - 1)
dtbTable.Columns.Add(rdrDataReader.GetName(i), rdrDataReader.GetFieldType(i))
Next
dtbTable.BeginLoadData()
Dim values(rdrDataReader.FieldCount - 1) As Object
While rdrDataReader.Read
rdrDataReader.GetValues(values)
dtbTable.LoadDataRow(values, True)
End While
dtbTable.EndLoadData()
dtsData.Tables.Add(dtbTable)
msqlConnection.Close()
Return dtsData