c#小软件(SaveClassic)开发手记--（3）基础类（数据访问类DataAccess）
2011-12-07 09:32 zhaoyang 阅读(1531) 评论(2) 编辑 收藏 举报好些日子没整理自己的笔记了，实在是自己太忙了。我知道着不是借口，真是很累，根本就没有时间精力去整理这些笔记，现在稍微有点时间，我赶快整理一下思路。我想了想，今天还是把一些基本的类整理一下吧，这些都是我们在平常开发中经常见到的。这些内容，我自己感觉会有些毛病，希望大家帮忙改进一下，谢谢。
一、数据访问类DataAccess
数据访问类是我这个小软件最基础的类，它主要完成的功能就是，实现了对Access数据库的访问操作，具体代码如下。
using System.Data.OleDb;
using System.Data;
using System;
namespace Common
{
public class DataAccess
{
protected static OleDbConnection conn = new OleDbConnection();
protected static OleDbCommand comm = new OleDbCommand();
public static string connstring = "";
public DataAccess()
{
}
private static void openConnection()
{
if (conn.State == ConnectionState.Closed)
{
conn.ConnectionString = @"Provider=Microsoft.Jet.OleDb.4.0;Data Source=" + connstring;
comm.Connection = conn;
try
{
conn.Open();
}
catch (Exception e)
{ throw new Exception(e.Message); }
}
}
private static void closeConnection()
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
conn.Dispose();
comm.Dispose();
}
}
public static void excuteSql(string sqlstr)
{
try
{
openConnection();
comm.CommandType = CommandType.Text;
comm.CommandText = sqlstr;
comm.ExecuteNonQuery();
}
catch (Exception e)
{
throw new Exception(e.Message);
}
finally
{ closeConnection(); }
}//执行sql语句
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;
}//返回指定sql语句的OleDbDataReader对象，使用时请注意关闭这个对象。
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();
}
}
}//返回指定sql语句的OleDbDataReader对象,使用时请注意关闭
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 e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
return ds;
}//返回指定sql语句的dataset
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 e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
}//返回指定sql语句的dataset
public static DataTable dataTable(string sqlstr)
{
DataTable dt = new DataTable();
OleDbDataAdapter da = new OleDbDataAdapter();
try
{
openConnection();
comm.CommandType = CommandType.Text;
comm.CommandText = sqlstr;
da.SelectCommand = comm;
da.Fill(dt);
}
catch (Exception e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
return dt;
}//返回指定sql语句的datatable
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 e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
}//返回指定sql语句的datatable
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 e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
return dv;
}
}
}
这个类也许代码会有很多问题，请大家帮忙指正。
