dataadapter怎么用update方法做表间数据备份

dataadapter如何用update方法做表间数据备份
表t1,t2结构相同，用如下方法从t1表取数据并插入t2表，系统无任何出错提示，但是t2表无任何插入数据，代码如下：
OracleConnection oconn = new OracleConnection(GetConnString());
OracleDataAdapter oda = new OracleDataAdapter("select * from t1", oconn);
DataTable dt1 = new DataTable();
oda.Fill(dt1);
//以上取得t1表数据填充dt1
//以下用dt1更新t2表
OracleConnection oconn1 = new OracleConnection(GetConnString());
OracleDataAdapter oda1 = new OracleDataAdapter("select * from t2", oconn1);
OracleCommandBuilder ocb1 = new OracleCommandBuilder(oda1);
oconn1.Open();
oda1.Update(dt1);
dt1.AcceptChanges();
oconn1.Close();
问题不知出在那里？

[解决办法]

SQL code

OracleConnection oconn = new OracleConnection(GetConnString()); OracleDataAdapter oda = new OracleDataAdapter("select * from t1", oconn); DataTable dt1 = new DataTable(); oda.Fill(dt1); OracleConnection oconn1 = new OracleConnection(GetConnString()); oconn1.Open(); OracleDataAdapter oda1 = new OracleDataAdapter("select * from t2", oconn1); DataTable dt2 = new DataTable(); oda1.Fill(dt2); --更新資料foreach( DataRow row in dt1.Rows) {  try {    //import row :                   object [] row2 = row.ItemArray; dt2.BeginLoadData(); dt2.LoadDataRow(row2, false); dt2.EndLoadData(); } catch(Exception ex) {   throw ex; }}OracleCommandBuilder ocb1 = new OracleCommandBuilder(oda1); oda1.Update(dt2); dt2.AcceptChanges(); oconn1.Close();