我期待根據用戶輸入進行數據庫調用。我使用的行是:從Web應用程序動態調用數據庫
general_read.CommandText = "SELECT * FROM general WHERE Business_Name = '" & business_name & "';"
BUSINESS_NAME被動態加載從:
Protected Sub btnLoad_Click(sender As Object, e As System.EventArgs) Handles btnLoad.Click
business_name = txtName.Text
dbConnect()
dbGet()
dbDisconnect()
End Sub
的錯誤正在被所示:
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
我假設它與在數據庫調用之前未設置的變量有關,但我不完全確定。
'business_name'是全局聲明的嗎? – dpp
您可以通過單步執行代碼來判斷。是否在「general_read.CommandText = ...」上失敗 – Yatrix
是的,business_name是全局聲明的。問題是我只使用CommandText,並沒有設置連接字符串本身。 – Kruug