查找不同表的兩列的總和，然後減去其總和

Question

您好我想打一個查詢，先找到不同的表的兩列的總和，然後減去其 例 它是一個Visual Basic程序

Dim large_tbl As String 
Dim sell_large As String 

large_tbl = "SELECT Sum(No_Of_Bottle) FROM add_cotton where Cateogry='Large'" 
sell_large = "SELECT Sum(Quantity) FROM Sell_Detail where Cateogry='Large'" 

Adodc2.RecordSource = large_tbl - sell_large 

請幫助 它顯示了一個錯誤類型小姐比賽

Answer 1

兩個變量large_tbl和sell_large都是字符串 - 只是文字儘可能VB關注。您需要連接到數據源（即Sql Server）並執行查詢以獲得數字結果。

你要求計算機做的是從「blah」中減去「blah」並執行它。

我想你指的是更多的東西一樣：

Dim oCNX as ADODB.Connection 

:----Put code in here to open the connection to your database 

Dim resultA as ADODB.Recordset 
Dim resultB as ADODB.Recordset 

Dim large_tbl As String 
Dim sell_large As String 

large_tbl = "SELECT Sum(No_Of_Bottle) FROM add_cotton where Cateogry='Large'" 
sell_large = "SELECT Sum(Quantity) FROM Sell_Detail where Cateogry='Large'" 

Set resultA = oCNX.Execute(large_tbl) 
Set resultB = oCNX.Execute(sell_large) 

Do while not oRS.Eof() 

    Debug.Print "Result =" & (resultA(1).Value - resultB(1).Value) 

    oRS.MoveNext 
Loop 

或類似的東西。