人在旅途--一些DOT.NET的数据库(SQL)操作例子

人在旅途发表于 2008/3/28 16:41:17

转自http://qbar.qq.com/q100322/3115.htm using System;using System.Data;using System.Data.OleDb;namespace SysClassLibrary{ /// <summary> /// DataAccess 数据访问类 /// <description>数据处理基类,调用方式：DataAccess.DataSet((string)sqlstr);或者DataAccess.DataSet((string)sqlstr,ref DataSet ds); </description> /// </summary> public class DataAccess { #region 属性 protected static OleDbConnection conn=new OleDbConnection(); protected static OleDbCommand comm=new OleDbCommand(); #endregion public DataAccess() { //init(); } #region 内部函数静态方法中不会执行DataAccess()构造函数 /// <summary> /// 打开数据库连接 /// </summary> private static void openConnection() { if (conn.State == ConnectionState.Closed) { //SysConfig.ConnectionString 为系统配置类中连接字符串 conn.ConnectionString = SysConfig.ConnectionString; comm.Connection =conn; try { conn.Open(); } catch(Exception e) { throw new Exception(e.Message); } } } /// <summary> /// 关闭当前数据库连接 /// </summary> private static void closeConnection() { if(conn.State == ConnectionState.Open) conn.Close(); conn.Dispose(); comm.Dispose(); } #endregion /// <summary> /// 执行Sql查询语句 /// </summary> /// <param name="sqlstr">传入的Sql语句</param> public static void ExecuteSql(string sqlstr) { try { openConnection(); comm.CommandType =CommandType.Text ; comm.CommandText =sqlstr; comm.ExecuteNonQuery(); } catch(Exception ex) { throw new Exception(ex.Message); } finally { closeConnection(); } } /// <summary> /// 执行Sql查询语句并返回第一行的第一条记录,返回值为object 使用时需要拆箱操作 -> Unbox /// </summary> /// <param name="sqlstr">传入的Sql语句</param> /// <returns>object 返回值 </returns> public static object ExecuteScalar(string sqlstr) { object obj=new object(); try { openConnection(); comm.CommandType =CommandType.Text ; comm.CommandText =sqlstr; obj=comm.ExecuteScalar(); } catch(Exception ex) { throw new Exception(ex.Message); } finally { closeConnection(); } return obj; } /// <summary> /// 执行Sql查询语句,同时进行事务处理 /// </summary> /// <param name="sqlstr">传入的Sql语句</param> public static void ExecuteSqlWithTransaction(string sqlstr) { closeConnection(); openConnection(); OleDbTransaction trans; trans=conn.BeginTransaction(); comm.Transaction =trans; try { openConnection(); comm.CommandType =CommandType.Text ; comm.CommandText =sqlstr; comm.ExecuteNonQuery(); trans.Commit(); } catch { trans.Rollback(); } finally { closeConnection(); } } /// <summary> /// 返回指定Sql语句的OleDbDataReader，请注意，在使用后请关闭本对象，同时将自动调用closeConnection()来关闭数据库连接 /// 方法关闭数据库连接 /// </summary> /// <param name="sqlstr">传入的Sql语句</param> /// <returns>OleDbDataReader对象</returns> public static OleDbDataReader DataReader(string sqlstr) { OleDbDataReader dr=null; try { openConnection(); comm.CommandText =sqlstr; comm.CommandType =CommandType.Text ; dr=comm.ExecuteReader(CommandBehavior.CloseConnection); } catch { try { dr.Close(); closeConnection(); } catch { } } return dr; } /// <summary> /// 返回指定Sql语句的OleDbDataReader，请注意，在使用后请关闭本对象，同时将自动调用closeConnection()来关闭数据库连接 /// 方法关闭数据库连接 /// </summary> /// <param name="sqlstr">传入的Sql语句</param> /// <param name="dr">传入的ref DataReader 对象</param> public static void DataReader(string sqlstr,ref OleDbDataReader dr) { try { openConnection(); comm.CommandText =sqlstr; comm.CommandType =CommandType.Text ; dr=comm.ExecuteReader(CommandBehavior.CloseConnection); } catch { try { if(dr!=null && !dr.IsClosed) dr.Close(); } catch { } finally { closeConnection(); } } } /// <summary> /// 返回指定Sql语句的DataSet /// </summary> /// <param name="sqlstr">传入的Sql语句</param> /// <returns>DataSet</returns> public static DataSet DataSet(string sqlstr) { DataSet ds= new DataSet(); OleDbDataAdapter da=new OleDbDataAdapter(); try { openConnection(); comm.CommandType =CommandType.Text ; comm.CommandText =sqlstr; da.SelectCommand =comm; da.Fill(ds); } catch(Exception ex) { throw new Exception(ex.Message); } finally { closeConnection(); } return ds; } /// <summary> /// 返回指定Sql语句的DataSet /// </summary> /// <param name="sqlstr">传入的Sql语句</param> /// <param name="ds">传入的引用DataSet对象</param> public static void DataSet(string sqlstr,ref DataSet ds) { OleDbDataAdapter da=new OleDbDataAdapter(); try { openConnection(); comm.CommandType =CommandType.Text ; comm.CommandText =sqlstr; da.SelectCommand =comm; da.Fill(ds); } catch(Exception ex) { throw new Exception(ex.Message); } finally { closeConnection(); } } /// <summary> /// 返回指定Sql语句的DataTable /// </summary> /// <param name="sqlstr">传入的Sql语句</param> /// <returns>DataTable</returns> public static DataTable DataTable(string sqlstr) { OleDbDataAdapter da=new OleDbDataAdapter(); DataTable Datatable=new DataTable(); try { openConnection(); comm.CommandType =CommandType.Text ; comm.CommandText =sqlstr; da.SelectCommand =comm; da.Fill(Datatable); } catch(Exception ex) { throw new Exception(ex.Message); } finally { closeConnection(); } return Datatable; } /// <summary> /// 执行指定Sql语句,同时给传入DataTable进行赋值 /// </summary> /// <param name="sqlstr">传入的Sql语句</param> /// <param name="dt">ref DataTable dt </param> public static void DataTable(string sqlstr,ref DataTable dt) { OleDbDataAdapter da=new OleDbDataAdapter(); try { openConnection(); comm.CommandType =CommandType.Text ; comm.CommandText =sqlstr; da.SelectCommand =comm; da.Fill(dt); } catch(Exception ex) { throw new Exception(ex.Message); } finally { closeConnection(); } } /// <summary> /// 返回指定Sql语句的DataView /// </summary> /// <param name="sqlstr">传入的Sql语句</param> /// <returns>DataView</returns> public static DataView DataView(string sqlstr) { OleDbDataAdapter da=new OleDbDataAdapter(); DataView dv=new DataView(); DataSet ds=new DataSet(); try { openConnection(); comm.CommandType=CommandType.Text; comm.CommandText =sqlstr; da.SelectCommand =comm; da.Fill(ds); dv=ds.Tables[0].DefaultView; } catch(Exception ex) { throw new Exception(ex.Message); } finally { closeConnection(); } return dv; } }}

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