猫の気ままなC#日記

		デザインパターンのサンプルを掲載してます。このカテゴリの更新はかなり不定期です。

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DataBase.cs ��N��X

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.Common;

namespace Cancer.ADO
{
    public class  DataBase
    {
        // �����o�ϐ�
        private DbConnection _connection = null;
        private DbCommand _command = null;

        // �v���p�e�B
        public virtual DbConnection Connection
        {
            get
            {
                return _connection;
            }
        }
        public virtual DbCommand Command
        {
            get
            {
                return _command;
            }
        }

        // ���\�b�h
        public virtual void Open()
        {
            Connection.Open();
        }

        public virtual void Close()
        {
            Connection.Close();
        }
        public virtual void Fill(DataSet ds)
        {
            ;
        }
        public virtual void UpDate(DataSet ds)
        {
            ;
        }
    }
}

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DBMSAccess.cs

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.Common;
using System.Data.OleDb;

namespace Cancer.ADO
{
    public class DBMSAccess : DataBase
    {
        // �����o�ϐ�
        private OleDbConnection _connection = null;
        private OleDbCommand _command = null;

        // �R���X�g���N�^
        public DBMSAccess()
        {
            _connection = new OleDbConnection();
            _command = new OleDbCommand();
        }

        // �v���p�e�B
        public override DbConnection Connection
        {
            get
            {
                return _connection;
            }
        }
        public override DbCommand Command
        {
            get
            {
                return _command;
            }
        }
    }
}

��悤��SQLServer��PostgreSQL��쐬��܂��B

DBSQLServer.cs

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.Common;
using System.Data.SqlClient;

namespace Cancer.ADO
{
    public class DBSQLServer : DataBase
    {
        private SqlConnection _connection = null;
        private SqlCommand _command = null;

        public DBSQLServer()
        {
            _connection = new SqlConnection();
            _command = new SqlCommand();
        }
        public override DbConnection Connection
        {
            get
            {
                return _connection;
            }
        }
        public override DbCommand Command
        {
            get
            {
                return _command;
            }
        }
    }
}

DBPostgreSQL.cs

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.Common;
using Npgsql;

namespace Cancer.ADO
{
    public class DBPostgreSQL : DataBase
    {
        // �����o�ϐ�
        private NpgsqlConnection _connection = null;
        private NpgsqlCommand _command = null;

        // �R���X�g���N�^
        public DBPostgreSQL()
        {
            _connection = new NpgsqlConnection();
            _command = new NpgsqlCommand();
        }

        // �v���p�e�B
        public override DbConnection Connection
        {
            get
            {
                return _connection;
            }
        }
        public override DbCommand Command
        {
            get
            {
                return _command;
            }
        }

        // ���\�b�h
        public override void Fill(DataSet ds)
        {
            using (NpgsqlDataAdapter adapter = new NpgsqlDataAdapter())
            {
                _command.Connection = _connection;
                adapter.SelectCommand = _command;
                adapter.Fill(ds);
            }
        }
        public override void UpDate(DataSet ds)
        {
            using (NpgsqlDataAdapter adapter = new NpgsqlDataAdapter())
            {
                _command.Connection = _connection;
                adapter.Update(ds);
            }
        }

    }
}

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DBFactory.cs

using System;
using System.Collections.Generic;
using System.Text;

namespace Cancer.ADO
{
    public class DBFactory
    {
        // �񋓑�
        public enum DBType
        {
            MSAccess,
            SQLServer,
            PostgreSQL,
        }

        // ���\�b�h
        public static DataBase DataBaseFactory(DBType type)
        {
            switch (type)
            {
                case DBType.MSAccess:
                    return new DBMSAccess();

                case DBType.SQLServer:
                    return new DBSQLServer();

                case DBType.PostgreSQL:
                    return new DBPostgreSQL();
            }
            return new DataBase();
        }
    }
}

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�ڑ��DB��PostgreSQL�Ƃ��܂��B

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private void button1_Click(object sender, EventArgs e)
{
    // PosgreSQL��p�̃N���X�̃C���X�^���X���쐬���܂��B
    // �����ł�DBPostgreSQL�N���X�ƂȂ�܂��B
    DataBase db = DBFactory.DataBaseFactory(DBFactory.DBType.PostgreSQL);

    // DBPostgreSQL�N���X�̃C���X�^���X���쐬�������_��
    // �֘A�N���X��DbConnection��NpgsqlConnection�Ő������܂��B
    db.Connection.ConnectionString = "Server=localhost;Port=5432;User Id=[���[�U��];Password=[�p�X���[�h];Database=[�f�[�^�x�[�X��];";

    // �ڑ����܂��B
    db.Open();

    // �f�[�^���擾���܂��B
    DataSet ds = new DataSet();
    db.Command.CommandText = "SELECT * FROM m_hyouhin";
    db.Fill(ds);

    // �������܂��B
    db.Close();
}

db.Connection.ConnectionString��[��[�U��][�p�X��[�h][�f�[�^�x�[�X]�͓K��Ȓl��Ă��B
DBPostgreSQL��Npgsql�v��o�C�_�[�𗘗p��Ă��܂��B
Npgsql�̓l�b�g��_�E��[�h��Ă��B
http://pgfoundry.org/frs/?group_id=1000140