c# - 在 ASP.NET Core Web API 中处理脏数据的最佳方法

Question

我目前正在研究asp.Net Core Web API的程序设计，但我对以下问题没有任何想法。

假设有一个支付功能，它必须在调用支付网关之前检查 Db 中的账户余额，然后更新账户余额。如何确保没有脏数据，同时只执行 1 条 SQL 语句？

标签： c#databaseasp.net-core-webapi

Answer 1

您必须为付款操作开始新的交易。

private static void DoPayment(string connectionString)
{
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        connection.Open();

        SqlCommand command = connection.CreateCommand();
        SqlTransaction transaction;

        // Start a local transaction.
        transaction = connection.BeginTransaction("SampleTransaction");

        // Must assign both transaction object and connection
        // to Command object for a pending local transaction
        command.Connection = connection;
        command.Transaction = transaction;

        try
        {
            command.CommandText =
                "Insert into Region (RegionID, RegionDescription) VALUES (100, 'Description')";
            command.ExecuteNonQuery();
            command.CommandText =
                "Insert into Region (RegionID, RegionDescription) VALUES (101, 'Description')";
            command.ExecuteNonQuery();

            // Attempt to commit the transaction.
            transaction.Commit();
            Console.WriteLine("Both records are written to database.");
        }
        catch (Exception ex)
        {
            Console.WriteLine("Commit Exception Type: {0}", ex.GetType());
            Console.WriteLine("  Message: {0}", ex.Message);

            // Attempt to roll back the transaction.
            try
            {
                transaction.Rollback();
            }
            catch (Exception ex2)
            {
                // This catch block will handle any errors that may have occurred
                // on the server that would cause the rollback to fail, such as
                // a closed connection.
                Console.WriteLine("Rollback Exception Type: {0}", ex2.GetType());
                Console.WriteLine("  Message: {0}", ex2.Message);
            }
        }
    }
}

详细https://docs.microsoft.com/en-us/dotnet/api/system.data.sqlclient.sqltransaction