这个是我的
using System;
using System.Data;
using System.Data.OleDb;
using System.Configuration;namespace Ccshop.App_Code.DAL
{
/// <summary>
/// SqlHelper 的摘要说明。
/// </summary>
/// public class SqlHelper:System.Web.UI.Page
{
public SqlHelper()
{
} public string Con_Str()
{
if (ConString == null)
{
ConString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath(ConfigurationSettings.AppSettings["DSN"]);
if (ConString == null)
{
throw new Exception("无可用数据库连接");
}
}
return ConString;
}
private static string ConString;
//返回DataSet
public static DataSet ds(string cmdText)
{
OleDbCommand cmd = new OleDbCommand();
OleDbConnection conn = new OleDbConnection (ConString); cmd.CommandText=cmdText;
cmd.Connection=conn; try
{
OleDbDataAdapter da=new OleDbDataAdapter();
da.SelectCommand=cmd; DataSet ds = new DataSet();
da.Fill(ds);
return ds;
}
catch
{
throw;
}
} //返回datatable
public static DataTable dtable(string cmdText)
{
OleDbCommand cmd = new OleDbCommand();
OleDbConnection conn = new OleDbConnection (ConString); cmd.CommandText=cmdText;
cmd.Connection=conn; OleDbDataAdapter myadp1= new OleDbDataAdapter();
DataSet ds1=new DataSet(); DataTable mytable1;
try
{
conn.Open();
myadp1.SelectCommand=cmd;
myadp1.Fill(ds1,"news");
mytable1=ds1.Tables["news"];
}
finally
{
conn.Close();
}
return mytable1;
}
}
}
--------------------------------------------------------------------------------报错是:
ConnectionString 属性尚未初始化。
应该怎么做啊?????
using System;
using System.Data;
using System.Data.OleDb;
using System.Configuration;namespace Ccshop.App_Code.DAL
{
/// <summary>
/// SqlHelper 的摘要说明。
/// </summary>
/// public class SqlHelper:System.Web.UI.Page
{
public SqlHelper()
{
} public string Con_Str()
{
if (ConString == null)
{
ConString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath(ConfigurationSettings.AppSettings["DSN"]);
if (ConString == null)
{
throw new Exception("无可用数据库连接");
}
}
return ConString;
}
private static string ConString;
//返回DataSet
public static DataSet ds(string cmdText)
{
OleDbCommand cmd = new OleDbCommand();
OleDbConnection conn = new OleDbConnection (ConString); cmd.CommandText=cmdText;
cmd.Connection=conn; try
{
OleDbDataAdapter da=new OleDbDataAdapter();
da.SelectCommand=cmd; DataSet ds = new DataSet();
da.Fill(ds);
return ds;
}
catch
{
throw;
}
} //返回datatable
public static DataTable dtable(string cmdText)
{
OleDbCommand cmd = new OleDbCommand();
OleDbConnection conn = new OleDbConnection (ConString); cmd.CommandText=cmdText;
cmd.Connection=conn; OleDbDataAdapter myadp1= new OleDbDataAdapter();
DataSet ds1=new DataSet(); DataTable mytable1;
try
{
conn.Open();
myadp1.SelectCommand=cmd;
myadp1.Fill(ds1,"news");
mytable1=ds1.Tables["news"];
}
finally
{
conn.Close();
}
return mytable1;
}
}
}
--------------------------------------------------------------------------------报错是:
ConnectionString 属性尚未初始化。
应该怎么做啊?????
可以
在类里添加一个数据域保存ConString的值;
在方法里引用数据域的值;
using System;
using System.ComponentModel;
using System.Collections;
using System.Diagnostics;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;namespace nmhz.components
{
/// <summary>
/// Dbconnection 的摘要说明。
/// </summary>
public class Dbconnection
{
// 连接数据源
public SqlConnection con;
public Dbconnection()
{
//
// TODO: 在此处添加构造函数逻辑
//
}
/// <summary>
/// 打开数据库连接.
/// </summary>
public void Open()
{
// 打开数据库连接
if (con == null)
{
con = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]);
}
if(con.State ==System.Data.ConnectionState.Closed)
con.Open(); } /// <summary>
/// 关闭数据库连接
/// </summary>
public void Close()
{
if (con != null)
con.Close();
} /// <summary>
/// 释放资源
/// </summary>
public void Dispose()
{
// 确认连接是否已经关闭
if (con != null)
{
con.Dispose();
con = null;
}
}
}
}
String ConString==null; if (ConString == null) { ConString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath(ConfigurationSettings.AppSettings["DSN"]); if (ConString == null) { throw new Exception("无可用数据库连接"); } } return ConString; }
然后在你的每一个函数内需要用这个字符串直接调用这个函数怎么样!