Question

我有一个MS Access数据库，如下所示

Filing_Year     |  Name
------------------------
02/01/2008      | AAA             
02/01/2008      | AAA             
02/03/2008      | AAA             
03/01/2008      | BBB

我需要在C＃中进行查询，它将获得如下输出并将其显示在gridview

中

Filing_Year     | file_count
----------------------------
02/01/2008      | 2  
02/03/2008      | 1  
03/01/2008      | 1

这是我尝试过的代码：

dataGridView1.Columns.Add("Column", "FileCount");    // file count is not an element in database

OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;DataSource=|DataDirectory|\RMS_Database.mdb");

con.Open();

OleDbDataAdapter sda = new OleDbDataAdapter("select Filing_Year,count(*) from Checklist_Data group by Filing_Year ", con);

DataTable dt = new DataTable();
sda.Fill(dt);

BindingSource bSource = new BindingSource();
bSource.DataSource = dt;

dataGridView1.DataSource = bSource;
sda.Update(dt);

有了这个，我只看到唯一的filing_year，而不是计数。

提前致谢。非常感谢帮助。

Answer 1

您需要修改SQL查询，如：

SELECT Filing_Year, COUNT(Name) as file_count
FROM Checklist_Data 
GROUP BY Filing_Year, Name

如何使用C＃查找MS Access数据库中不同记录的数量？

1 个答案: