Question

C#winForm中连接Access数据库的问题！！！！

private void Form1_Load(object sender, EventArgs e)
{
string strPath = Application.StartupPath + "db_09.mdb";
string ConStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data source=" + strPath;
//string ConStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data source=" + "C:\\Users\\lenovo\\Desktop\\db_09.mdb";
OleDbConnection oleCon = new OleDbConnection(ConStr);
OleDbDataAdapter oleDap = new OleDbDataAdapter("select*from 账目",oleCon);
DataSet ds = new DataSet();
oleDap.Fill(ds, "账目");
this.dataGridView1.DataSource = ds.Tables[0].DefaultView;
oleCon.Dispose();

}
为啥我这段代码什么都显示不出来。。我是新手。。才开始学。。学不明白。。求指教

Answer 1

using System;
namespace StudentContactSoft
{
    public static class AccessHelper
    {
      public static string strCon = 
           @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Directory.GetCurrentDirectory() + "\\data\\ClientData.mdb;Persist Security Info = True";
           ///通过传入的SQL查询语句获取数据集
      public static DataSet GetDataSet(string strsql)
      {
        DataSet ds = new DataSet();
        try
        {
          using (OleDbConnection con = new OleDbConnection(strCon))
          {
           if (con.State != ConnectionState.Open)
           {
              con.Open();
           }
           OleDbDataAdpter adapter - new OleDbDataAdapter(strsql, con);
           adapter.Fill(ds);
           return ds;
          }
        }
        catch (OleDbException odbException)
        {
          throw odbException;
        }
      }
      ///返回受影响的行数，常用以更新，插入，删除等功能
      public static int  ExecuteNonquery(string sql)
      {
         try 
         {
           using (OleDbConnection con = new OleDbConnection(strCon)
           {
              if (con.State != ConnectionState.Open)
              {
                con.Open();
              }
              OleDbCommand cmd = new OleDbCommand();
              cmd.Connection =con;
              cmd.CommandText = sql;
              OleDbTransaction ts = con.BeginTransaction();
              cmd.Transaction = ts;

              int h = cmd.ExecuteNonQuery();
              if(h>0)
              {
                ts.commit();
              }
              else
              {
                ts.Rollback();
              }
              return h;
           }
         }
         catch (OleDbException ex)
         {
           throw ex
         }
      }
      ///返回第一行第一列的值
      public static object ExcuteScare(string sql)
      {
         try 
         {
           using (OleDbConnection con = new OleDbConnection(strCon))
           {
             if (con.State != ConnectionState.Open)
             {
                 con.Open();
             }
             using (OleDbCommand cmd = new OleDbCommand(sql,con))
             {
              return cmd.ExecuteScalar();
             }
           }
         }
         catch (OleDbException odbException)
         {
           throw odbException;
         }
      }
}

Answer 2

有三个地方需注意:
1、没有数据库的登录账号和密码。
2.少了一句 oleCon.open() 来打开连接
3.最好用try-catch 来捕捉异常

Answer 3

你应该是少了一个路径符：
string strPath = Application.StartupPath + "\\db_09.mdb";

追问

我加上了。。还是什么都显示不出来

Answer 4

oleCon.Open();