可重用数据库操作基本类

using System;


using System.Data;


using System.Configuration;


using System.Data.SqlClient;


using System.Text;






/**//// SQL数据库操作对象命名空间


namespace DBO




...{




/**//// 数据条目类，用来方便转换数据项目成各种格式


public class DateItem




...{


private Object fObject;




public DateItem(Object dataObj)




...{


if (dataObj == null)


throw new System.ArgumentNullException("数据条目对象参数不能为空");


fObject = dataObj;


}




//转换成字符串类型,DBnull转换为""


public override string ToString()




...{


string result = "";


if (!(fObject is DBNull))


result = fObject.ToString().TrimEnd(null);


return result;


}




//转换成数字类型,DBnull默认转换成0


public int ToInt()




...{


int result = 0;


int.TryParse(ToString(), out result);


return result;


}




//转换成日期类型


public DateTime ToDateTime()




...{


DateTime result = DateTime.Now;


result = System.Convert.ToDateTime(ToString());


return result;


}




//转换成bool型


public bool toBool()




...{


//尝试转换字符串


if (ToString().ToLower() == "true")


return true;


else if (ToString().ToLower() == "false")


return false;


else if (ToInt() != 0)


return true;


else


return false;


}


}






//数据库操作基础类


public class DBA




...{


//配置文件中连接字符串的名称


private static string CONN_STRING = "pc";


private string fQueryString;




// 当前数据游标位置


private int fCurIndex = 0;


private string fConnString;




private SqlConnection fConnection;


private SqlCommand fCommand;


private SqlDataAdapter fDataAdapter;


private DataSet fDataSet;


private SqlTransaction fsqlTrans;




public DBA()




...{


fConnString = GetConnString();


InitSQL("", null);


}




public DBA(string queryStr, params SqlParameter[] cmdParms)




...{


fConnString = GetConnString();


InitSQL(queryStr, cmdParms);


}




//初始化数据访问对象


private void InitSQL(string qString, SqlParameter[] cmdParms)




...{


fQueryString = qString;


fConnection = new SqlConnection(fConnString);


fConnection.Open();




fCommand = new SqlCommand();


fCommand.Connection = fConnection;


fCommand.CommandType = CommandType.Text;


fCommand.CommandText = fQueryString;


if (cmdParms != null)


PrepareSqlParms(fCommand, cmdParms);




fDataAdapter = new SqlDataAdapter();


fDataAdapter.SelectCommand = fCommand;




fDataSet = new DataSet();




if (fQueryString.Length > 0)


fDataAdapter.Fill(fDataSet);




}




//静态方法,SQL字符串清理:替换单引号


private static string sqlEncode(string sqlString)




...{


StringBuilder sb = new StringBuilder();


for (int i = 0; i < sqlString.Length; i++)


sb.Append((sqlString[i] == ''') ? "''" : sqlString[i].ToString());


return sb.ToString();


}




//静态方法,给SqlCommand对象设定参数


private static void PrepareSqlParms(SqlCommand sqlCmd, SqlParameter[] cmdParms)




...{


sqlCmd.Parameters.Clear();


if (cmdParms.Length > 0)




...{


foreach (SqlParameter parm in cmdParms)


sqlCmd.Parameters.Add(parm);


}


}




//静态方法,返回DB连接字符串


public static string GetConnString()




...{


return ConfigurationManager.ConnectionStrings[CONN_STRING].ConnectionString;


}




//静态方法,用来执行执行一个查询(insert、update、delete)，返回受影响的行数。


public static int ExecuteNonQuery(string queryString, params SqlParameter[] cmdParms)




...{


int result;


using (SqlConnection sqlConn = new SqlConnection(GetConnString()))




...{


sqlConn.Open();


SqlCommand sqlCmd = new SqlCommand(sqlEncode(queryString), sqlConn);


PrepareSqlParms(sqlCmd, cmdParms);


result = sqlCmd.ExecuteNonQuery();


sqlCmd.Parameters.Clear();


sqlConn.Close();


}


return result;


}




//静态方法,执行一个查询(count()、sum()等统计函数)，返回结果集中第一行的第一列。


public static Object ExecuteScalar(string queryString, params SqlParameter[] cmdParms)




...{


Object result;


using (SqlConnection sqlConn = new SqlConnection(GetConnString()))




...{


sqlConn.Open();


SqlCommand sqlCmd = new SqlCommand(sqlEncode(queryString), sqlConn);


PrepareSqlParms(sqlCmd, cmdParms);


result = sqlCmd.ExecuteScalar();


sqlCmd.Parameters.Clear();


sqlConn.Close();


}


return result;


}




//静态方法,执行查询，返回sqlDataReader对象，Reader.Close()之后自动关闭连接


public static SqlDataReader QueryData(string queryString, params SqlParameter[] cmdParms)




...{


SqlConnection sqlConn = new SqlConnection(GetConnString());


sqlConn.Open();


SqlCommand sqlCmd = new SqlCommand(sqlEncode(queryString), sqlConn);


PrepareSqlParms(sqlCmd, cmdParms);


SqlDataReader sqlReader = sqlCmd.ExecuteReader(CommandBehavior.CloseConnection);


return sqlReader;


}




// 缺省索引器


public DateItem this[string index]




...{


get




...{


object result;


try




...{


result = fDataSet.Tables[0].Rows[fCurIndex][index];


}


catch (ArgumentException e)




...{


result = "无此字段名(" + index + ")<br> " + e.Message;


}


catch (Exception e)




...{


result = "结果集中无记录<br> " + e.Message;


}


return new DateItem(result);


}


}




// 向后移动数据游标


public bool MoveNext()




...{


if (!EOF)




...{


fCurIndex++;


return true;


}


return false;


}




// 是否到达数据尾部


public bool EOF




...{




get ...{ return fCurIndex >= Count; }


}




//当前索引


public int CurrentIndex




...{




get ...{ return fCurIndex; }


}




public int Count




...{




get ...{ return Rows.Count; }


}




// 表的行集


public DataRowCollection Rows




...{




get ...{ return fDataSet.Tables[0].Rows; }


}




// 表的列集


public DataColumnCollection Columns




...{


get




...{


return fDataSet.Tables[0].Columns;


}


}




// 提供一个可供利用的数据源


public DataView DataSource




...{




get ...{ return fDataSet.Tables[0].DefaultView; }


}




// 执行已有查询，返回受影响的行数，结果集装载到内置对象中。


public int ReOpen()




...{


return fDataAdapter.Fill(fDataSet);


}




// 执行一个查询，返回受影响的行数，结果集装载到内置对象中。用于执行select。


public int Open(string queryString, params SqlParameter[] cmdParms)




...{


int result;


fQueryString = queryString;


fCommand.CommandText = fQueryString;


PrepareSqlParms(fCommand, cmdParms);


if (fsqlTrans != null)


fCommand.Transaction = fsqlTrans;


fDataSet.Clear();


result = fDataAdapter.Fill(fDataSet);


return result;


}




//执行一个查询返回影响行数


public int Execute(string queryString, params SqlParameter[] cmdParms)




...{


fQueryString = queryString;


fCommand.CommandText = fQueryString;


PrepareSqlParms(fCommand, cmdParms);


if (fsqlTrans != null)


fCommand.Transaction = fsqlTrans;


return fCommand.ExecuteNonQuery();


}




//开始一个事务操作


public void BeginTransaction()




...{


if ((fsqlTrans != null) && (fConnection != null))


fsqlTrans = fConnection.BeginTransaction();


}




//提交事务


public void Commit()




...{


if (fsqlTrans != null)




...{


fsqlTrans.Commit();


fsqlTrans = null;


}


}




//回滚事务


public void Rollback()




...{


if (fsqlTrans != null)




...{


fsqlTrans.Rollback();


fsqlTrans = null;


}


}




// 释放数据库连接。


public void Close()




...{


if (fDataSet != null)


fDataSet.Dispose();


if (fConnection != null)




...{


fConnection.Close();


fConnection.Dispose();


}


if (fCommand != null)


fCommand.Dispose();


if (fDataAdapter != null)


fDataAdapter.Dispose();


}


}


}