DbHelper数据操作类

     其实,微软的企业库中有一个非常不错的数据操作类了.但是,不少公司(起码我遇到的几个...),对一些"封装"了些什么的东西不太敢用,虽然我推荐过微软的企业库框架了...但是还是要"评估"...一评就是几个月...而且,一些公司有的根本就是裸ado.net开发,或者自己封装的数据库操作类非常别扭,很不好用.
      这里我给大家共享一个我参照企业库中的数据操作组件编码风格写的数据库操作类,对使用它的程序员来说,编码是很舒服滴(起码我觉得很好撒).以下是代码,很简单的,没有做任何多余的封装,只是改变了ADO.NET的编码步骤,方便了具体开发数据库操作代码的程序员.
     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;
        }

        //
增加参数#region 增加参数
         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

        //
执行#region 执行
         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         

        //
执行事务#region 执行事务
         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();
            }
        }
    }
//那么如何使用它呢?下面我给出一些基本的使用示例,基本能满足你大部分的数据库操作需要了.
//1)直接执行sql语句

        DbHelper db 
=   new  DbHelper();
        DbCommand cmd 
=  db.GetSqlStringCommond( " insert t1 (id)values('haha') " );
        db.ExecuteNonQuery(cmd);
//2)执行存储过程

        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)输入参数/输出参数/返回值的使用(比较重要哦)

        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)事务的使用.(项目中需要将基本的数据库操作组合成一个完整的业务流时,代码级的事务是必不可少的哦)
    pubic  void  DoBusiness()
    {
        
using  (Trans t  =   new  Trans())
        {
            
try
            {
                D1(t);
                
throw   new  Exception(); // 如果有异常,会回滚滴
                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);
    }



'以上我们好像没有指定数据库连接字符串,大家如果看下DbHelper的代码,就知道要使用它必须在config中配置两个参数,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>
'其实,DbHelper需要的仅仅是两个字符串,你可以自己修改,作成加密什么的...

好了,就这样,DbHelper的代码是非常简单和透明的,只是在ado.net上做了一点小包装,改变了一下使用它的程序员的编码方式,去除掉一些比较"物理级"的编程概念,如connection的open和close之类的,使程序员更专注于业务逻辑代码的编写,少死掉点脑细胞,另外,统一了数据操作层的数据操作代码的风格和格式,维护起来很方便的撒~~~

另:以上代码大家可以随意使用, 不需要给我版权费的啦,嘿嘿.如果大家发现有什么BUG,或者有更好的数据操作类的实现方式,请联系我哦.

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