如何计算表中按类别划分的行数 [英] How Can I Count The Number Of Rows By Category In A Table

问题描述

我正在使用MS Access 2007.



在桌面1

1 ID

2项目

3块

4批



在桌面2

1 ID

2项目

3计数





它会变成这样



表1

ID项目块很多

1 FOREST 1 1

2 HOUSE 1 5

3 FOREST 5 8

4 FOREST 4 6

5 HOUSE 4 8



table 2

ID项目计数

1 FOREST 3

2 HOUSE 2





i想知道table1上的每个项目有多少然后它会显示在table2 row3





这是我的代码：

I'm using MS Access 2007.

On table1
1 ID
2 Project
3 Block
4 Lot

On table2
1 ID
2 Project
3 Count


It will become like this

table 1
ID PROJECT BLOCK LOT
1 FOREST 1 1
2 HOUSE 1 5
3 FOREST 5 8
4 FOREST 4 6
5 HOUSE 4 8

table 2
ID PROJECT COUNT
1 FOREST 3
2 HOUSE 2


i want to know how many per project on table1 then it will show on table2 row3


this is my code:

Try
            Dim cmd As OleDbCommand = New OleDbCommand("SELECT (Select COUNT(PROJECT) FROM table1 WHERE PROJECT=FOREST as Project12Count)", con)
            opendatabase()
            Dim myDA As OleDbDataAdapter = New OleDbDataAdapter(cmd)
            Dim myDataSet As DataSet = New DataSet()
            myDA.Fill(myDataSet, "MyTable95")
            DataGridView1.DataSource = myDataSet.Tables("MyTable95").DefaultView
            closedatabase()
        Catch ex As Exception
            MessageBox.Show(ex.ToString)
        Finally
            closedatabase()
        End Try

我曾尝试搜索许多可以使用的代码帮助我，但我找不到任何可以解决我的问题。



感谢任何可以帮助我的人。

Ive tried searching many codes that can help me but i cant find anything that can solve my problem.

Thanks to anyone who can help me.

推荐答案

试试这个：

Try this:

SELECT Project, COUNT(Project) FROM Table1
GROUP BY Project

应该给你想要的数字 - 但我可能不会将它存储在一个单独的表格中，因为它很容易与真实数字不同步。

That should give you the numbers you want - but I probably wouldn't store it in a separate table as it's far, far too easy for that to get out of synch which the "real" numbers.

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