DbFactory常见实现思路

Question

我正在尝试创建一个公共数据层来连接到所有公共数据库。所以我开始创建 DbFactory class.

在创建这个工厂时我应该考虑哪些事情，比如可伸缩性、性能、安全性、连接池和可重用性。请指教

这是我开始的：

public class DbFactory
{
    private DbConnection _dbConnection;

    public DbConnection GetDbConnection(DbType type)
    {
        switch (type)
        {
            case (DbType.Oracle):
                _dbConnection = new OracleConnection();
                break;
            case (DbType.SqlServer):
                _dbConnection = new SqlConnection();
                break;
            case (DbType.Excel):
                _dbConnection = new OleDbConnection();
                break;
            case (DbType.Other):
                _dbConnection = new OdbcConnection();
                break;
            default:
                _dbConnection = new OdbcConnection();
                break;
        }

        return _dbConnection;
    }

    public enum DbType
    {
        SqlServer,
        Oracle,
        Excel,
        Other
    }
}

Answer 1

我建议不要这样做。使用这种方式对我来说违反了SRP and OCP from the SOLID principles at minimum. It also looks like YAGNI。

更好的方法是创建一个简单的界面，例如：

public interface IConnectionFactory
{
    DbConnection GetNewConnection();
}

您可以根据需要为每种类型的数据库创建一个实现。对于 SQL 这看起来像：

public class SqlConnectionFactory : IConnectionFactory
{
    private readonly string connectionString;

    public SqlConnectionFactory(string connectionString)
    {
         this.connectionString = connectionString;
    }

    public DbConnection GetNewConnection()
    {
         return new SqlConnection(this.connectionString);
    }
}

根据您正在处理的当前应用程序，您可以注入当时所需的正确实现。例如：

public class SomeServiceNeedingDatabaseConnection
{
     private readonly IConnectionFactory connectionFactory;

     public SomeServiceNeedingDatabaseConnection(IConnectionFactory connectionFactory)
     {
          this.connectionFactory = connectionFactory;
     }

     public void SomeMethodNeedingDatabase()
     {
          using (var connection = this.connectionFactory.GetNewConnection())
          {
                 // Do something with connection
          }
     }
}

在您的应用程序的某个地方，最好是在您的应用程序的 composition root 中，您可以创建 ConnectionFactory.

所需的实现

DbFactory常见实现思路

DbFactory Common Implementation Ideas

c#

database

factory

dbconnection