数据层抽象工厂

Question

我是开发抽象工厂模式的新手,并希望在数据层中创建一个抽象工厂,它将帮助我将该层链接到任何其他数据库,例如sql和oracle.你能帮我完成这项任务吗？请注意,数据库的连接字符串将在此层中找到,而不是在演示文稿中.

谢谢

EDITED

public abstract class Database
{
    public string connectionString;

    #region Abstract Functions

    public abstract IDbConnection CreateConnection();
    public abstract IDbCommand CreateCommand();
    public abstract IDbConnection CreateOpenConnection();
    public abstract IDbCommand CreateCommand(string commandText, IDbConnection connection);
    public abstract IDbCommand CreateStoredProcCommand(string procName, IDbConnection connection);
    public abstract IDataParameter CreateParameter(string parameterName, object parameterValue);

    #endregion
}

---

public class SQLDatabase : Database
{
    public override IDbConnection CreateConnection()
    {
        return new SqlConnection(connectionString);
    }

    public override IDbCommand CreateCommand()
    {
        return new SqlCommand();
    }

    public override IDbConnection CreateOpenConnection()
    {
        SqlConnection connection = (SqlConnection)CreateConnection();
        connection.Open();

        return connection;
    }

    public override IDbCommand CreateCommand(string commandText, IDbConnection connection)
    {
        SqlCommand command = (SqlCommand)CreateCommand();

        command.CommandText = commandText;
        command.Connection = (SqlConnection)connection;
        command.CommandType = CommandType.Text;

        return command;
    }

    public override IDbCommand CreateStoredProcCommand(string procName, IDbConnection connection)
    {
        SqlCommand command = (SqlCommand)CreateCommand();

        command.CommandText = procName;
        command.Connection = (SqlConnection)connection;
        command.CommandType = CommandType.StoredProcedure;

        return command;
    }

    public override IDataParameter CreateParameter(string parameterName, object parameterValue)
    {
        return new SqlParameter(parameterName, parameterValue);
    }
}

那是我创建的两个班级..

Answer 1

功能已存在.

将连接字符串添加到app/webb.config:

<connectionStrings>
    <add name="TheDatabase" providerName="System.Data.OleDb" connectionString="Provider=OraOLEDB.Oracle.1;Persist Security Info=False;User Id=xxx;Password=yyy;Data Source=zzzz;Extended Properties="/>
  </connectionStrings>

使用工厂构建连接:

var connectionString = ConfigurationManager.ConnectionStrings["TheDatabase"];
var providerName = connectionString.ProviderName;
var factory = DbProviderFactories.GetFactory(providerName);

获得连接:

var connection = factory.CreateConnection();

获取命令:

var command == connection.CreateCommand();

您唯一需要做的就是在app/web.config中切换驱动程序.无需其他更改.

更新

public class Database
{
    public static IDbConnection CreateOpenConnection()
    {
        var connectionString = ConfigurationManager.ConnectionStrings["TheDatabase"];
        var providerName = connectionString.ProviderName;
        var factory = DbProviderFactories.GetFactory(providerName);
        var connection = factory.CreateConnection();
        connection.Open();
        return connection;
    }
}

class FlowerManager : DataWorker
{
    public static void GetFlowers()
    {
        using (IDbConnection connection = Database.CreateOpenConnection())
        {
            using (IDbCommand command = connection.CreateCommand("SELECT * FROM FLOWERS", connection))
            {
                using (IDataReader reader = command.ExecuteReader())
                {
                    // ...
                }
            }
        }
    }
}