Best way to merge two Datatables

Question

I need to marge two datatables with condition. I have a datatable where the data comes from a local XML Database and another datatable where the data comes from a remote SQL Server. If any update made in the remote datatable I need to update/merge with the local datatable. Here is what I have so far: ``` Public Sub MargeTwoTable() Dim SQL As String = "" Dim RemoteTable As New DataTable Dim LocalTable As DataTable Dim dal As New DalComon Dim yy As Integer = 0 Dim UpdateDate As String Dim TableName As String = "V_Book_Price" LocalTable = LoadDataTable(TableName, True) UpdateDate = LocalTable.Compute("MAX(update_date)", Nothing) SQL = "select * from V_Book_Price where Update_Date > '" & UpdateDate & "'" RemoteTable = dal.GetDataSetBySQL(SQL).Tables(0) If RemoteTable.Rows.Count > 0 Then For i = 0 To RemoteTable.Rows.Count - 1 Dim st As DataRow Dim mm() As DataRow = LocalTable.Select("ID = '" & RemoteTable.Rows(i).Item("ID") & "'") If mm.Length = 0 Then st = LocalTable.NewRow For yy = 0 To…

Accepted Answer

Not sure if can be applicable, but have you ever looked at the DataTable.LoadDataRow() method?. It seems a good candidate to substitute all of you code above.

Your code could be simplified to these lines

```
Dim row as DataRow
For Each row in RemoteTable.Rows
    LocalTable.LoadDataRow(row.ItemArray, false)
Next
```

Another alternative could be the DataTable.Merge that could cut your code to a single line

```
LocalTable.Merge(RemoteTable, False)
```

However, the real effectiveness of these two methods depends on the schema compatibility and from the presence of AutoNumber (identity) columns.

Best way to merge two Datatables

Solution

Problem