Dim tran As System.Data.SqlClient.SqlTransaction
try
    Dim conn As new System.Data.SqlClient.SqlConnection("server=voyo;uid=sa;pwd=hailun.;database=Test")
    conn.Open() \'打开链接
    tran = conn.BeginTransaction()
    Dim copy As new System.Data.SqlClient.SqlBulkCopy(conn, System.Data.SqlClient.SqlBulkCopyOptions.Default, tran)
    For Each dc As DataCol In DataTables("表A").datacols
        Dim mapping1 As new System.Data.SqlClient.SqlBulkCopyColumnMapping(dc.name, dc.name)
        Copy.ColumnMappings.Add(mapping1)
    Next
    copy.Destinati \'指定服务器上目标表的名称
    copy.BatchSize = 1000
    copy.WriteToServer(DataTables("表D").basetable)   \'你的datatable名字,执行把DataTable中的数据写入DB
    tran.Commit()                                  \'提交事务
    msgbox("OK")
catch ex As exception
    msgbox(ex.message)
    tran.Rollback()    \'返回False 执行失败!
End try

有条件的执行复制要怎么写了？