我希望根据用户输入进行数据库调用。我正在使用的线路是:
general_read.CommandText = "SELECT * FROM general WHERE Business_Name = '" & business_name & "';"
business_name 从以下位置动态加载:
Protected Sub btnLoad_Click(sender As Object, e As System.EventArgs) Handles btnLoad.Click
business_name = txtName.Text
dbConnect()
dbGet()
dbDisconnect()
End Sub
显示的错误是:
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
我假设它与在进行数据库调用之前未设置的变量有关,但我并不完全确定。