c# - MySQL -> 事务上下文 -> 代码审查

Question

我希望有人可以检查我是如何使用 Transaction with MySql 的上下文。我相信这应该适用于下面的大纲。有人可以看看我的代码并告诉我我做的是否正确吗？谢谢。

我相信这应该:

• 实例化数据库连接。
• 遍历给定 DataTable 的 DataTable 行。
• 检查表是否存在，如果不存在，将执行创建表。
• 执行带有信息参数的插入命令到新创建的或现有的表中。

• 提交事务然后关闭连接。

      //Open the SQL Connection
      var dbConnection = new MySqlConnection(GetConnectionString(WowDatabase));
      dbConnection.Open();
      //Instantiate the Command
      using (var cmd = new MySqlCommand())
      {
          //Create a new Transaction
          using (var transaction = dbConnection.BeginTransaction())
          {
              uint lastId = 999999;
              for (int i = 0; i < dt.Rows.Count; i++)
              {
                  //var identifier = dt.Rows[i].Field<int>("Identifier");
                  var id = dt.Rows[i].Field<uint>("Entry");
                  var name = dt.Rows[i].Field<string>("Name");
                  var zone = dt.Rows[i].Field<uint>("ZoneID");
                  var map = dt.Rows[i].Field<uint>("MapID");
                  var state = dt.Rows[i].Field<Enums.ItemState>("State");
                  var type = dt.Rows[i].Field<Enums.ObjectType>("Type");
                  var faction = dt.Rows[i].Field<Enums.FactionType>("Faction");
                  var x = dt.Rows[i].Field<float>("X");
                  var y = dt.Rows[i].Field<float>("Y");
                  var z = dt.Rows[i].Field<float>("Z");
                  string dataTableName = "entry_" + id;
                  //Create Table if it does not exist.
                  if (id != lastId)
                  {
                      cmd.CommandText = $"CREATE TABLE IF NOT EXISTS `{dataTableName}` (" +
                                        "`identifier`   int NOT NULL AUTO_INCREMENT COMMENT 'Auto Incriment Identifier' ," +
                                        "`zone_id`      int NULL COMMENT 'Zone Entry' ," +
                                        "`x_axis`       float NULL COMMENT 'X Axis on Map' ," +
                                        "`y_axis`       float NULL COMMENT 'Y Axis on Map' ," +
                                        "`z_axis`       float NULL COMMENT 'Z Axis on Map' ," +
                                        "`situation`    enum('') NULL COMMENT 'Location of the item. Underground, Indoors, Outdoors)' ," +
                                        "`faction`      enum('') NULL COMMENT 'Specifies the Faction which can safely access the item.' ," +
                                        "PRIMARY KEY(`identifier`)" +
                                        ")";
                      cmd.ExecuteNonQuery();
                      lastId = id;
                  }
                  //Create command to execute the insertion of Data into desired Table
                  cmd.CommandText = $"INSERT INTO [{dataTableName}] " +
                                         "([identifier], [zone_id], [x_axis], [y_axis], [z_axis], [situation], [faction], [Create_Date], [Update_Date]) " +
                                         "VALUES (@Identifier, @Zone_Id, @X_Axis, @Y_Axis, @Z_Axis, @Situation, @Faction, @Create_Date, @Update_Date)";
                  //Add data value with Parameters.
                  cmd.CommandType = CommandType.Text;
                  //cmd.Parameters.AddWithValue("@Identifier", identifier);
                  cmd.Parameters.AddWithValue("@Identifier", id);
                  cmd.Parameters.AddWithValue("@Zone_Id", zone);
                  cmd.Parameters.AddWithValue("@X_Axis", x);
                  cmd.Parameters.AddWithValue("@Y_Axis", y);
                  cmd.Parameters.AddWithValue("@Z_Axis", z);
                  cmd.Parameters.AddWithValue("@Situation", state);
                  cmd.Parameters.AddWithValue("@Faction", faction);
                  cmd.Parameters.AddWithValue("@Create_Date", DateTime.Now.Date);
                  cmd.Parameters.AddWithValue("@Update_Date", DateTime.Now.Date);
  
                  cmd.ExecuteNonQuery();
              } //for (int i = 0; i < dt.Rows.Count; i++)
  
              //Commit the Transaction
              transaction.Commit();
          } //using (var transaction = dbConnection.BeginTransaction())
      } //using (var cmd = new MySqlCommand())
  
      //Close the Connection
      dbConnection.Close();
  

Answer 1

我认为这不会(如预期的那样)与 MySql 一起工作。有一些语句会导致隐式提交 - CREATE TABLE 就是其中之一。

http://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html