simple but urgent request

i have db with 3 tables

1. emp_master (emp_id, emp_name, emp_pasword)
2. task_master (task_id, task_name, task_starttime, task_completiontime, task_endtime)
3. task_status (emp_id, task_id, task_date,task_statusflag)

first i need a dataset for the above filled with data, next i want to generate an xml file for the above database, then i will send that xml file to mobile pc..

in mobile pc application, i need to generate dataset from that xml... and i will need to update the dataset... which will inturn update the xml file...

back in my pc i will use that xml file to update my database....

please give me code for this... i am unable to write by myself... because i am new to xml and dataset...

i need it urgent... help!!!!!

I'm new to it, too. Here is a function I use for dumping some tables into an XML string:

VB Code:

'This creates the XML string to be exported. Only new data goes if typ is 1. Otherwise
    'ALL of the data goes.
    Private Function MakeOutput(ByVal typ As Integer) As String
        Dim lDadapt As System.Data.SqlServerCe.SqlCeDataAdapter
        Dim lDset As New System.Data.DataSet
        Dim st1 As String
        Dim cmd As System.Data.SqlServerCe.SqlCeCommand
 
        Try
            cmd = dbM.GetCommand
        Catch ex As Exception
            MsgBox("Database is not valid.")
            MakeOutput = ""
            Exit Function
        End Try
 
        Try
            If typ = 1 Then
                cmd.CommandText = "SELECT * FROM EffortTable WHERE Downloaded < 2"
                'Get the tables and put them in the dataset.
                lDadapt = New System.Data.SqlServerCe.SqlCeDataAdapter(cmd)
                lDadapt.Fill(lDset, "EffortTable")
                lDadapt.Dispose()
                cmd.CommandText = "SELECT * FROM FishTable WHERE Downloaded < 2 "
                lDadapt = New System.Data.SqlServerCe.SqlCeDataAdapter(cmd)
                lDadapt.Fill(lDset, "FishTable")
                lDadapt.Dispose()
                cmd.CommandText = "SELECT * FROM MaxAnglerNumber WHERE Downloaded < 2 "
                lDadapt = New System.Data.SqlServerCe.SqlCeDataAdapter(cmd)
                lDadapt.Fill(lDset, "MaxAnglerNumber")
 
                'This may not be the best way to do this, but get a string of the XML.
                st1 = lDset.GetXml()
            Else
                cmd.CommandText = "SELECT * FROM EffortTable"
                'Get the tables and put them in the dataset.
                lDadapt = New System.Data.SqlServerCe.SqlCeDataAdapter(cmd)
                lDadapt.Fill(lDset, "EffortTable")
                lDadapt.Dispose()
                cmd.CommandText = "SELECT * FROM FishTable"
                lDadapt = New System.Data.SqlServerCe.SqlCeDataAdapter(cmd)
                lDadapt.Fill(lDset, "FishTable")
                lDadapt.Dispose()
                cmd.CommandText = "SELECT * FROM MaxAnglerNumber"
                lDadapt = New System.Data.SqlServerCe.SqlCeDataAdapter(cmd)
                lDadapt.Fill(lDset, "MaxAnglerNumber")
 
                'This may not be the best way to do this, but get a string of the XML.
                st1 = lDset.GetXml()
            End If
            MakeOutput = st1
        Catch ex As System.Data.SqlServerCe.SqlCeException
            MakeOutput = ""
        End Try
    End Function

And a function for reading in new data from the XML

VB Code:

Private Function GetTables(ByVal stXML As String) As Boolean
        Dim retVal As Integer
        Dim dSet As New System.Data.DataSet
        Dim sRead As System.IO.StringReader
        Dim xmlTxtR As System.Xml.XmlTextReader
        Dim cmd As System.Data.SqlServerCe.SqlCeCommand
        Dim dTable As System.Data.DataTable
        Dim rw As System.Data.DataRow
 
 
        'This should take what was passed in and turn it into a string.
        sRead = New System.IO.StringReader(stXML)
 
        xmlTxtR = New System.Xml.XmlTextReader(sRead)
        dSet.ReadXml(xmlTxtR, XmlReadMode.InferSchema)
 
        'Now we need to kill off anything that is in the shift or location table, because if 
        'there is anything in there that is not in the incoming thing, you are basically ****ed.
 
        'However, this could also mean that you should clear the data from the database, but that
        'is probably NOT a very good idea, because actual data is lost. Residual data associated
        'with table entries that no longer exist are a problem on the downstream side, not the 
        'upstream side.
        Try
            cmd = dbM.GetCommand
            cmd.CommandText = ("DELETE FROM ShiftTable")
            cmd.ExecuteNonQuery()
            cmd.CommandText = ("DELETE FROM LocationTable")
            cmd.ExecuteNonQuery()
        Catch ex As System.Data.SqlServerCe.SqlCeException
            MsgBox(ex.Message)
        End Try
 
        'Now the data from the dataset must be shifted to the table.
        dTable = dSet.Tables("ShiftTable")
        For Each rw In dTable.Rows
            cmd.CommandText = ("INSERT INTO ShiftTable (ShiftName) VALUES(?)")
            cmd.Parameters.Add("ShiftName", rw.Item("ShiftName"))
            cmd.ExecuteNonQuery()
            cmd.Parameters.Clear()
        Next
 
        dTable = dSet.Tables("LocationTable")
        For Each rw In dTable.Rows
            cmd.CommandText = ("INSERT INTO LocationTable (LocationName) VALUES(?)")
            cmd.Parameters.Add("LocationName", rw.Item("LocationName"))
            cmd.ExecuteNonQuery()
            cmd.Parameters.Clear()
        Next
 
        cmd.Dispose()
        sRead.Close()
        xmlTxtR.Close()
        GetTables = True
    End Function

You should be able to modify this fairly simply to whatever you are trying to do. I have no idea whether this is an optimal solution or not, but it is a workable one.