web.config的配置
<appSettings>
<add key="Configpath" value="~/XmlConfig/webset.config"/>
<add key="DbPath" value="~/App_Data/test.mdb"/>
</appSettings>
DbHelperOleDb.cs 的类方法
//数据库连接字符串（web.config来配置），可以动态更改connectionString支持多数据库。
public static string connectionString=ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString.ToString()+HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings["DbPath"])+";";
执行一条计算查询，返回查询结果（object）
public static object GetSingle(string SQLString)
{
using(OleDbConnection connection=new OleDbConnection(connectionString))
{
using (OleDbCommand cmd=new OleDbCommand(SQLString,connection))
{
try
{
connection.Open();
object obj=cmd.ExecuteScalar();
if(Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch(system.Data.OleDb.OleDbException e)
}
}
}
执行查询语句 返回OleDbDataReader
public static OleDbDataReader ExecuteReader(string strSQL)
{
OleDbConnection connection =new OleDbConnection (connectionString);
OleDbCommand cmd=new OleDbCommand(strSQL,connetction)
try
{
connection.Open();
OleDbDataReader myReader=cmd.ExecuteReader();
return myReader;
}
catch(System.Data.OleDb.OleDbException e)
{
throw new Exception(e.Message);
}
}
执行查询语句 ， 返回DataSet
Public static DataSet Query(string SQLString)
{
using (OleDbConnection connection=new OleDbConnection(connectionString))
{
DataSet ds=new DataSet();
try
{
connection.Open();
OleDbDataAdapter command=new OleDbDataAdapter(SQLString,connection);
command.Fill(ds,"ds");
}
catch(System.Data.OleDb.OleDbException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}