Shulou(Shulou.com)06/02 Report--

This article mainly introduces "what are the ADO.NET transaction processing methods". In the daily operation, I believe that many people have doubts about the ADO.NET transaction processing methods. The editor consulted all kinds of data and sorted out simple and easy-to-use operation methods. I hope it will be helpful for you to answer the doubts about "what are the ADO.NET transaction processing methods?" Next, please follow the editor to study!

ADO.NET transaction processing method:

◆ BeginTrans: start 1 transaction

◆ CommitTrans: commits the transaction and writes the operations in the transaction to the data source.

◆ RollBackTrans: rolls back the transaction and cancels the operation.

When updating multiple tables at the same time, transactions must be used to ensure data consistency. For example, there are two tables, one is the expenditure table and the other is the balance table. When an expense is spent, the expenditure cost increases and the balance decreases. Both tables need to be updated at the same time, but if there is no transaction, if an error occurs after updating the expenditure table, the balance table is not updated, which is not up to the requirements. At this point, they should be sealed into a transaction. Ensure the integrity of multi-table operations. In addition, it can also be used to encapsulate the multi-step operation of the same table, making the multi-step operation a single unit.

In general, we add an error capture statement for On Error Goto ErrNum at BeginTrans, and then use RollBackTrans to cancel the transaction in the error handler. It looks like:

Cn.BeginTrans on Error Goto ErrNum... Update Table 1... Update Table 2... Cn.CommitTrans Exit Sub ErrNum: cn.RollBackTrans msgbox / / error prompt

Transactions can be nested, and a long integer returned by the begintrans method indicates which layer the current transaction is. For example, return 1 means that the current transaction is not included in any transaction. CommitTrans and RollBackTrans end the transaction opened by the most recent BeginTrans. After starting a transaction with begintrans in the program, you should use the committrans or rollbacktrans method to end. If not, all transactions will be rolled back after the end of the program, that is, the system will not commit any transactions automatically. ADO.NET transaction methods such as:

Cn.BeginTrans rst.MoveNext cn.Execute "insert into BB values ('John shop', 'aaa',0,'0','0',0,'0')" cn.CommitTrans

There are two situations that need to be explained: problems may also occur in the transaction, resulting in forced abandonment of the transaction: one is that a critical field is locked and cannot be written; the other is that the field value is out of range, such as the field is Integer, but the actual value is greater than 32767, the field is Text, but the value string length is more than 32K, and so on, which will cause the transaction to be forced to abandon.

At this point, the study of "what are the ADO.NET transaction processing methods" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.