mysql事务（提交和回滚）(mysql transaction (commit and rollback))

 下面是我用于MySqlTransaction的代码，它运行得很完美....但问题是因为我使用的是mysql命令的单个实例，我必须在其中使用唯一的PARAMETER。 这毁了我的查询。 有没有其他方法可以做.... 
 
 我尝试在每次查询后处置cmd但没有用.. :( 
 
 
          con.Open()
            Dim sqlTran As MySqlTransaction = con.BeginTransaction()
            Dim cmd As MySqlCommand = con.CreateCommand()
            cmd.Transaction = sqlTran
            Dim str As String = Nothing
            Try
                cmd.CommandText = "SELECT myid FROM memaster where    Adate=@adate and ANo=@ano and ASource=@asrc"
                cmd.Parameters.AddWithValue("@adate", txt_bpass_adate.Text)
                cmd.Parameters.AddWithValue("@ano", txt_bpass_af.Text)
                cmd.Parameters.AddWithValue("@asrc", txt_bpass_asource.Text)
                str = cmd.ExecuteScalar()
                'cmd.Dispose()'
                If str Is Nothing Then

                    cmd.CommandText = "Insert into memaster (ADate,ANo,ASource) values (@aDate,@aNo,@aSRC)"
                    cmd.Parameters.AddWithValue("@aDate", txt_bpass_adate.Text)
                    cmd.Parameters.AddWithValue("@aNo", txt_bpass_af.Text)
                    cmd.Parameters.AddWithValue("@aSRC", txt_bpass_asource.Text)

     cmd.ExecuteNonQuery()
    End If
     sqlTran.Commit()

            Catch ex As Exception
                Try
                    sqlTran.Rollback()
                Catch ex1 As Exception

                End Try
            End Try
 
 
 我实际上想在单个事务中触发超过4个查询，这样如果出现任何问题我可以回滚它... 
 
 如果有人有任何其他方法，请与我分享这个概念... 
 
 
     For index As Integer = 1 To 5
                    cmd.CommandText = "Insert into detail (ID,BNos,SNo) values (@FID1,@BNo,@SeqN1)"
                    cmd.Parameters.AddWithValue("@FID1", str)
                    cmd.Parameters.AddWithValue("@BNo", str1)
                    cmd.Parameters.AddWithValue("@SeqN1", txt_bpass_sqn1.Text)
                    cmd.ExecuteNonQuery()


                Next

below is the code i am using for MySqlTransaction and it is running perfectly.... but problem is as i am using single instance of mysqlcommand i have to use unique PARAMETER in it. which is ruining my query. is there any other way around to do....
 
i tried to dispose cmd after each query but of no use.. :( 
 
 
          con.Open()
            Dim sqlTran As MySqlTransaction = con.BeginTransaction()
            Dim cmd As MySqlCommand = con.CreateCommand()
            cmd.Transaction = sqlTran
            Dim str As String = Nothing
            Try
                cmd.CommandText = "SELECT myid FROM memaster where    Adate=@adate and ANo=@ano and ASource=@asrc"
                cmd.Parameters.AddWithValue("@adate", txt_bpass_adate.Text)
                cmd.Parameters.AddWithValue("@ano", txt_bpass_af.Text)
                cmd.Parameters.AddWithValue("@asrc", txt_bpass_asource.Text)
                str = cmd.ExecuteScalar()
                'cmd.Dispose()'
                If str Is Nothing Then

                    cmd.CommandText = "Insert into memaster (ADate,ANo,ASource) values (@aDate,@aNo,@aSRC)"
                    cmd.Parameters.AddWithValue("@aDate", txt_bpass_adate.Text)
                    cmd.Parameters.AddWithValue("@aNo", txt_bpass_af.Text)
                    cmd.Parameters.AddWithValue("@aSRC", txt_bpass_asource.Text)

     cmd.ExecuteNonQuery()
    End If
     sqlTran.Commit()

            Catch ex As Exception
                Try
                    sqlTran.Rollback()
                Catch ex1 As Exception

                End Try
            End Try
 
 
i actually want to fire more then 4 queries in single transaction so that if anything go wrong i can rollback it...
 
if any onebody have any other method of it kindly share the concept wid me... 
 
 
     For index As Integer = 1 To 5
                    cmd.CommandText = "Insert into detail (ID,BNos,SNo) values (@FID1,@BNo,@SeqN1)"
                    cmd.Parameters.AddWithValue("@FID1", str)
                    cmd.Parameters.AddWithValue("@BNo", str1)
                    cmd.Parameters.AddWithValue("@SeqN1", txt_bpass_sqn1.Text)
                    cmd.ExecuteNonQuery()


                Next

原文：https://stackoverflow.com/questions/14252560