i have 4 computers in network.
when i press a button i need to delete a table from computer 2,3,4 and i need to copy that table from computer 1 to 2,3,4.
and this file is a table inside a .mdb file. so i can't use "FILECOPY(sOURCE,DESTINATION)".
Eg: if the path is "c:\Programs\data.mdb" ,then Emp is one of the table inside that data.mdb. and i don't need to delete entire data.mdb, i need to delete only that "Emp" table and i don't need to copy entire data.mdb, i need to copy only "Emp" table and save it in computers 2,3,4.
if anyone have anyidea how to delete and copy this table inside .mdb file, to other computers in network.
if you have any idea please let me know. and if you can provide eg: that will be great help for me.
thanks in advance.
remya1000
09-17-2007, 11:01 AM
i tried this code....
Dim nPath As String = "\\t1\root\Programs"
Dim strConn1 As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & nPath & "\DataTables.mdb"
Dim strSQL1 As String = "Select * from Employees"
Dim myConnection1 As New OleDbConnection(strConn1)
myConnection1.Open()
Dim myCommand1 As New OleDbCommand(strSQL1, myConnection1)
Dim myReader1 As OleDbDataReader = myCommand1.ExecuteReader
While myReader1.Read
Dim nPath2 As String = "\\t2\root\Programs"
Dim strConn2 As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & nPath2 & "\Terminal.mdb"
Dim strSQL2 As String = "insert into Employees (EmpID, FirstName, LastName, AccessN0,CardNo,InsuranceNo) values (" & Trim(myReader1(0)) & ", '" & Trim(myReader1(1)) & "', '" & Trim(myReader1(2)) & "', " & Trim(myReader1(3)) & ", " & Trim(myReader1(4)) & ", " & Trim(myReader1(5)) & ", " & Trim(myReader1(6)) & ") "
Dim myConnection2 As New OleDbConnection(strConn2)
myConnection2.Open()
Dim myCommand2 As New OleDbCommand(strSQL2, myConnection2)
myCommand2.ExecuteNonQuery()
End While
myReader1.Close()
myConnection1.Close()
Sometimes some of the fields will be blank. and while trying to insert the values to computer 2 from computer 1 error occurs as
Error:
------
"An unhandled exception of type 'System.InvalidCastException' occurred in microsoft.visualbasic.dll. Additional information: Cast from type 'DBNull' to type 'String' is not valid."
if anyone have anyidea what's wrong in my codes please help me.
thanks in advance.
lmf232s
09-17-2007, 11:43 AM
You need to check the columns of your table.
For the error you listed the table can not convert a Null to a string. You could create a function that turns that null into a string and that should eliminate that problem.
Say its FirstName giving you the problem then do something like this in the sql statement.
myCstr(Trim(myReader1(1)))
Public Function myCstr(ByVal Value as String) as String
If IsDBNull(Value) Then
Return ("")
Else
Return CStr(Test)
End If
End Function
as far as the blank columns go make sure that you had data in the table where you copied it from and make sure you mapped your columns correclty.
remya1000
09-17-2007, 01:31 PM
Dim nPath As String = "\\t1\root\Programs"
Dim strConn1 As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & nPath & "\DataTables.mdb"
Dim strSQL1 As String = "Select * from Emp"
Dim myConnection1 As New OleDbConnection(strConn1)
myConnection1.Open()
Dim myCommand1 As New OleDbCommand(strSQL1, myConnection1)
Dim myReader1 As OleDbDataReader = myCommand1.ExecuteReader
While myReader1.Read
Dim nPath2 As String = "t2\\root\Programs"
Dim strConn2 As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & nPath2 & "\DataTable.mdb"
Dim myConnection2 As New OleDbConnection(strConn2)
myConnection2.Open()
Dim myCommand2 As New OleDbCommand(strSQL2, myConnection2)
myCommand2.ExecuteNonQuery()
End While
Public Function CheckNull(ByVal Value As String) As String
If IsDBNull(Value) Then
Return ("")
ElseIf Value = "." Then
Return ("")
ElseIf Value = "" Then
Return ("")
Else
Return CStr(Value)
End If
End Function
and while running its passing through SQL. and that its taking vlues too. and i'm pasting that SQL taking values during run time here.
and when it reach this myCommand2.ExecuteNonQuery() line error occurs as below.
Error
-----
An unhandled exception of type 'System.Data.OleDb.OleDbException' occurred in system.data.dll
if anyone have anyidea what's the mistake i did in my codes, please let me know. please help me...
thanks in advance...
lmf232s
09-17-2007, 04:00 PM
you have 2 places where this value appears
, .,
Should it possible be , '.',
lmf232s
09-17-2007, 04:02 PM
You could also wrap a
Try
'YOur code here
Catch ex As Exception
Response.write(err.Number & " - " & ex.Message)
End Try
remya1000
09-18-2007, 12:19 PM
as you said i changed that problem and now the SQL is this
Dim nPath As String = "\\t1\root\Programs"
Dim strConn1 As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & nPath & "\DataTables.mdb"
Dim strSQL1 As String = "Select * from Emp"
Dim myConnection1 As New OleDbConnection(strConn1)
myConnection1.Open()
Dim myCommand1 As New OleDbCommand(strSQL1, myConnection1)
Dim myReader1 As OleDbDataReader = myCommand1.ExecuteReader
While myReader1.Read
Dim nPath2 As String = "t2\\root\Programs"
Dim strConn2 As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & nPath2 & "\DataTable.mdb"
Dim myConnection2 As New OleDbConnection(strConn2)
myConnection2.Open()
Dim myCommand2 As New OleDbCommand(strSQL2, myConnection2)
myCommand2.ExecuteNonQuery()
End While
sometimes it take values from T1 and writes to T2. sometimes i get this error
"5 - Could not update; currently locked by user 'Admin' on machine 'T2'."
and before showing this error some of the records got saved in mdb. and ecah time the number of records enter in mdb before showing this error is random. sometime all the recorsd will be saved and it won't show this error too.
and database is not open while running the code. and no other calls are made to the database at that time too.
if you have any idea what's wrong in my codes please help me. and please let me know. please help me.
thanks in advance.
remya1000
09-19-2007, 09:19 AM
heah its working now......
that error occurs because myConnection2 is opening each time while its enter while loop but its not closing.
Thanks a lot for your help..... thanks a lot.....
Dim nPath As String = "\\t1\root\Programs"
Dim strConn1 As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & nPath & "\DataTables.mdb"
Dim strSQL1 As String = "Select * from Emp"
Dim myConnection1 As New OleDbConnection(strConn1)
myConnection1.Open()
Dim myCommand1 As New OleDbCommand(strSQL1, myConnection1)
Dim myReader1 As OleDbDataReader = myCommand1.ExecuteReader
While myReader1.Read
Dim nPath2 As String = "t2\\root\Programs"
Dim strConn2 As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & nPath2 & "\DataTable.mdb"
Try
Dim strSQL2 As String = "insert into Emp (EmployeeID, ...... ) " & _
"values (" & EmpId & ", .....) "
Dim myConnection2 As New OleDbConnection(strConn2)
myConnection2.Open()
Dim myCommand2 As New OleDbCommand(strSQL2, myConnection2)
myCommand2.ExecuteNonQuery()
Catch ex As Exception
MessageBox.Show(Err.Number & " - " & ex.Message)
End Try
Dim myConnection2 As New OleDbConnection(strConn2)
myConnection2.Open()
Dim myCommand2 As New OleDbCommand(strSQL2, myConnection2)
myCommand2.ExecuteNonQuery()
myConnectio2.Close()
End While