DbHelper數據操作類

fefef123 11年前發布 | 2K 次閱讀 C#

以下是代碼,很簡單的,沒有做任何多余的封裝,只是改變了ADO.NET的編碼步驟,方便了具體開發數據庫操作代碼的程序員.

    using System;
    using System.Data;
    using System.Data.Common;
    using System.Configuration;

public class DbHelper
{
    private static string dbProviderName = ConfigurationManager.AppSettings["DbHelperProvider"];
    private static string dbConnectionString = ConfigurationManager.AppSettings["DbHelperConnectionString"];

    private DbConnection connection;
    public DbHelper()
    {
        this.connection = CreateConnection(DbHelper.dbConnectionString);
    }
    public DbHelper(string connectionString)
    {
        this.connection = CreateConnection(connectionString);
    }
    public static DbConnection CreateConnection()
    {
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbConnection dbconn = dbfactory.CreateConnection();
        dbconn.ConnectionString = DbHelper.dbConnectionString;
        return dbconn;
    }
    public static DbConnection CreateConnection(string connectionString)
    {
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbConnection dbconn = dbfactory.CreateConnection();
        dbconn.ConnectionString = connectionString;
        return dbconn;
    }

    public DbCommand GetStoredProcCommond(string storedProcedure)
    {
        DbCommand dbCommand = connection.CreateCommand();
        dbCommand.CommandText = storedProcedure;
        dbCommand.CommandType = CommandType.StoredProcedure;
        return dbCommand;
    }
    public DbCommand GetSqlStringCommond(string sqlQuery)
    {
        DbCommand dbCommand = connection.CreateCommand();
        dbCommand.CommandText = sqlQuery;
        dbCommand.CommandType = CommandType.Text;
        return dbCommand;
    }

    #region 增加參數
    public void AddParameterCollection(DbCommand cmd, DbParameterCollection dbParameterCollection)
    {
        foreach (DbParameter dbParameter in dbParameterCollection)
        {
            cmd.Parameters.Add(dbParameter);
        }
    }
    public void AddOutParameter(DbCommand cmd, string parameterName, DbType dbType, int size)
    {
        DbParameter dbParameter = cmd.CreateParameter();
        dbParameter.DbType = dbType;
        dbParameter.ParameterName = parameterName;
        dbParameter.Size = size;
        dbParameter.Direction = ParameterDirection.Output;
        cmd.Parameters.Add(dbParameter);
    }
    public void AddInParameter(DbCommand cmd, string parameterName, DbType dbType, object value)
    {
        DbParameter dbParameter = cmd.CreateParameter();
        dbParameter.DbType = dbType;
        dbParameter.ParameterName = parameterName;
        dbParameter.Value = value;
        dbParameter.Direction = ParameterDirection.Input;
        cmd.Parameters.Add(dbParameter);
    }
    public void AddReturnParameter(DbCommand cmd, string parameterName, DbType dbType)
    {
        DbParameter dbParameter = cmd.CreateParameter();
        dbParameter.DbType = dbType;
        dbParameter.ParameterName = parameterName;
        dbParameter.Direction = ParameterDirection.ReturnValue;
        cmd.Parameters.Add(dbParameter);
    }
    public DbParameter GetParameter(DbCommand cmd, string parameterName)
    {
        return cmd.Parameters[parameterName];
    }

    #endregion

    #region 執行
    public DataSet ExecuteDataSet(DbCommand cmd)
    {
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();
        dbDataAdapter.SelectCommand = cmd;
        DataSet ds = new DataSet();
        dbDataAdapter.Fill(ds);
        return ds;
    }

    public DataTable ExecuteDataTable(DbCommand cmd)
    {
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();
        dbDataAdapter.SelectCommand = cmd;
        DataTable dataTable = new DataTable();
        dbDataAdapter.Fill(dataTable);
        return dataTable;
    }

    public DbDataReader ExecuteReader(DbCommand cmd)
    {
        cmd.Connection.Open();
        DbDataReader reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);            
        return reader;
    }
    public int ExecuteNonQuery(DbCommand cmd)
    {
        cmd.Connection.Open();
        int ret = cmd.ExecuteNonQuery();
        cmd.Connection.Close();
        return ret;
    }

    public object ExecuteScalar(DbCommand cmd)
    {
        cmd.Connection.Open();
        object ret = cmd.ExecuteScalar();
        cmd.Connection.Close();
        return ret;
    }
    #endregion        

    #region 執行事務
    public DataSet ExecuteDataSet(DbCommand cmd,Trans t)
    {
        cmd.Connection = t.DbConnection;
        cmd.Transaction = t.DbTrans;
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();
        dbDataAdapter.SelectCommand = cmd;
        DataSet ds = new DataSet();
        dbDataAdapter.Fill(ds);
        return ds;
    }

    public DataTable ExecuteDataTable(DbCommand cmd, Trans t)
    {
        cmd.Connection = t.DbConnection;
        cmd.Transaction = t.DbTrans;
        DbProviderFactory dbfactory = DbProviderFactories.GetFactory(DbHelper.dbProviderName);
        DbDataAdapter dbDataAdapter = dbfactory.CreateDataAdapter();
        dbDataAdapter.SelectCommand = cmd;
        DataTable dataTable = new DataTable();
        dbDataAdapter.Fill(dataTable);
        return dataTable;
    }

    public DbDataReader ExecuteReader(DbCommand cmd, Trans t)
    {
        cmd.Connection.Close();
        cmd.Connection = t.DbConnection;
        cmd.Transaction = t.DbTrans;            
        DbDataReader reader = cmd.ExecuteReader();
        DataTable dt = new DataTable();            
        return reader;
    }
    public int ExecuteNonQuery(DbCommand cmd, Trans t)
    {
        cmd.Connection.Close();
        cmd.Connection = t.DbConnection;
        cmd.Transaction = t.DbTrans;  
        int ret = cmd.ExecuteNonQuery();            
        return ret;
    }

    public object ExecuteScalar(DbCommand cmd, Trans t)
    {
        cmd.Connection.Close();
        cmd.Connection = t.DbConnection;
        cmd.Transaction = t.DbTrans;  
        object ret = cmd.ExecuteScalar();            
        return ret;
    }
    #endregion
}

public class Trans : IDisposable
{
    private DbConnection conn;
    private DbTransaction dbTrans;
    public DbConnection DbConnection
    {
        get { return this.conn; }
    }
    public DbTransaction DbTrans
    {
        get { return this.dbTrans; }
    }

    public Trans()
    {
        conn = DbHelper.CreateConnection();
        conn.Open();
        dbTrans = conn.BeginTransaction();
    }
    public Trans(string connectionString)
    {
        conn = DbHelper.CreateConnection(connectionString);
        conn.Open();
        dbTrans = conn.BeginTransaction();
    }
    public void Commit()
    {
        dbTrans.Commit();
        this.Colse();
    }

    public void RollBack()
    {
        dbTrans.Rollback();
        this.Colse();
    }

    public void Dispose()
    {
        this.Colse();
    }

    public void Colse()
    {
        if (conn.State == System.Data.ConnectionState.Open)
        {
            conn.Close();
        }
    }
}</pre> 


那么如何使用它呢?下面我給出一些基本的使用示例,基本能滿足你大部分的數據庫操作需要了.

1)直接執行sql語句


        DbHelper db = new DbHelper();
        DbCommand cmd = db.GetSqlStringCommond("insert t1 (id)values('haha')");
        db.ExecuteNonQuery(cmd);

2)執行存儲過程



        DbHelper db = new DbHelper();
        DbCommand cmd = db.GetStoredProcCommond("t1_insert");
        db.AddInParameter(cmd, "@id", DbType.String, "heihei");
        db.ExecuteNonQuery(cmd);


3)返回DataSet


        DbHelper db = new DbHelper();
        DbCommand cmd = db.GetSqlStringCommond("select * from t1");
        DataSet ds = db.ExecuteDataSet(cmd);


4)返回DataTable


        DbHelper db = new DbHelper();
        DbCommand cmd = db.GetSqlStringCommond("t1_findall");
        DataTable dt = db.ExecuteDataTable(cmd);


5)輸入參數/輸出參數/返回值的使用(比較重要哦)


        DbHelper db = new DbHelper();
        DbCommand cmd = db.GetStoredProcCommond("t2_insert");
        db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);
        db.AddOutParameter(cmd, "@outString", DbType.String, 20);
        db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);

        db.ExecuteNonQuery(cmd);

        string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter
        int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value


6)DataReader使用


        DbHelper db = new DbHelper();
        DbCommand cmd = db.GetStoredProcCommond("t2_insert");
        db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);
        db.AddOutParameter(cmd, "@outString", DbType.String, 20);
        db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);

        using (DbDataReader reader = db.ExecuteReader(cmd))
        {
            dt.Load(reader);
        }        
        string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter
        int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value


7)事務的使用.(項目中需要將基本的數據庫操作組合成一個完整的業務流時,代碼級的事務是必不可少的哦)

    pubic void DoBusiness()
    {
        using (Trans t = new Trans())
        {
            try
            {
                D1(t);
                throw new Exception();//如果有異常,會回滾滴
                D2(t);
                t.Commit();
            }
            catch
            {
                t.RollBack();
            }
        }
    }
    public void D1(Trans t)
    {
        DbHelper db = new DbHelper();
        DbCommand cmd = db.GetStoredProcCommond("t2_insert");
        db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);
        db.AddOutParameter(cmd, "@outString", DbType.String, 20);
        db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);

        if (t == null) db.ExecuteNonQuery(cmd);
        else db.ExecuteNonQuery(cmd,t);

        string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter
        int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value
    }
    public void D2(Trans t)
    {
        DbHelper db = new DbHelper();
        DbCommand cmd = db.GetSqlStringCommond("insert t1 (id)values('..')");        
        if (t == null) db.ExecuteNonQuery(cmd);
        else db.ExecuteNonQuery(cmd, t);
    }

以上我們好像沒有指定數據庫連接字符串,大家如果看下DbHelper的代碼,就知道要使用它必須在config中配置兩個參數,如下:


    <appSettings>
        <add key="DbHelperProvider" value="System.Data.SqlClient"/>
        <add key="DbHelperConnectionString" value="Data Source=(local);Initial Catalog=DbHelperTest;Persist Security Info=True;User ID=sa;Password=sa"/>
    </appSettings>



其實,DbHelper需要的僅僅是兩個字符串,你可以自己修改,作成加密什么的...

好了,就這樣,DbHelper的代碼是非常簡單和透明的,只是在ado.net上做了一點小包裝,改變了一下使用它的程序員的編碼方式,去除掉一些比較"物理級"的編程概念,如connection的open和close之類的,使程序員更專注于業務邏輯代碼的編寫,少死掉點腦細胞,另外,統一了數據操作層的數據操作代碼的風格和格式,維護起來很方便的撒~~~

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