1         private void 洱海各月出流流量frm_Load(object sender, EventArgs e)
 2         {
 3             //在查询按钮中用下面这段代码会出现打开数据库出错的现象
 4             MyTable1.Rows.Clear();
 5             //string msql = "Select 年 as Year order by 年 asc,全年平均 as YearAvr into YearAvrLL from 洱海各月出流流量";//新建表
 6            
 7             string MySQL = "Select * from 洱海各月出流流量 order by 年 asc";
 8 
 9             OleDbConnection MyConnection = new OleDbConnection(MyConnectionString);
10 
11             MyConnection.Open();
12 
13             OleDbDataAdapter MyAdatper = new OleDbDataAdapter(MySQL, MyConnection);
14             //OleDbDataAdapter MyAdatper1 = new OleDbDataAdapter(msql, MyConnection);
15 
16             MyAdatper.Fill(MyTable1);
17 
18             this.dataGridView1.DataSource = MyTable1;
19 
20             if (MyConnection.State == ConnectionState.Open)
21             {
22                 MyConnection.Close();
23             }
24            
25         }

 1         public string MyConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=ErLake.mdb";
 2 
 3         public System.Data.DataTable MyTable1 = new System.Data.DataTable();
 4 
 5         private void 查询_Click(object sender, EventArgs e)
 6         {
 7             MyTable1.Rows.Clear();
 8             string nyr1 = dateTimePicker1.Value.Date.ToString("yyyy-MM-dd");//yyyy-MM-dd正确提取和转换格式，用yyyy-mm-dd格式提取时月份会出错
 9             string[] tqn1 = nyr1.Split(‘-‘);                                //将提取到的yyyy-MM-dd，通过‘-’分割，存入数组
10             string nyr2 = dateTimePicker2.Value.Date.ToString("yyyy-MM-dd");//yyyy-MM-dd正确提取和转换格式，用yyyy-mm-dd格式提取时月份会出错
11             string[] tqn2 = nyr2.Split(‘-‘);                                //将提取到的yyyy-MM-dd，通过‘-’分割
12 
13             string sql = "select  * from 洱海各月出流流量 where 年 between ‘" + tqn1[0] + "‘ and ‘" + tqn2[0] + "‘ order by 年 asc";//通过修改数据库年字段的数据类型OK，数字类型改为文本类型
14 
15             OleDbConnection myCon = new OleDbConnection(MyConnectionString);
16             OleDbDataAdapter DA = new OleDbDataAdapter(sql, myCon);
17             DA.Fill(MyTable1);
18             dataGridView1.DataSource = MyTable1;
19 
20 
21 
22 
23         }