尝试“交易".首次...

本文介绍了尝试“交易".首次...的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

这是我第一次尝试使用交易...只是想知道我是否正确"完成了?看来还可以，但这并不代表什么. 只是尝试从数据表更新Access数据库.

This is the first time I''ve tried using a transaction... just wondering if I have done it "right"? It seems to work ok, but that doesn''t mean anything. Just trying to update an Access database from a datatable.

objConn.openConnection() Dim myTrans As OleDbTransaction = objConn.con.BeginTransaction() Dim cmd As New OleDbCommand cmd.Connection = objConn.con cmd.Transaction = myTrans Dim tRow As DataRow Dim sql As String Try For Each tRow In table.Rows sql = String.Format("UPDATE Pricing SET unitPrice = {0}, salesPrice = {1}, ProfitMargin = {2} WHERE ItemID = {3}", tRow(1), tRow(2), tRow(3), tRow(0)) cmd.CommandText = sql cmd.ExecuteNonQuery() Next myTrans.Commit() MessageBox.Show("Update Complete", "Vending", MessageBoxButtons.OK, MessageBoxIcon.Information) Catch ex As Exception MessageBox.Show(ex.ToString & vbCrLf & "Un-doing any work that has been done!", "Vending", MessageBoxButtons.OK, MessageBoxIcon.Error) myTrans.Rollback() Finally objConn.closeConnection() End Try

推荐答案

这已正确实施.如果要测试事务，请至少有2个表要在其中插入数据，并在将数据插入1个表后调用异常.这将回滚数据，而您不会在表中插入部分数据.这就是实现事务时的期望. This is implemented properly. If you want to test transaction, have atleast 2 tables where you intend to insert data and invoke an exception after data in inserted in 1 table. That would rollback the data and you don''t get partial data inserted in tables. This is what you expect when you implement transaction.