Question

我在这里有一个代码，它应该显示所有结果，从组合框中进行的选择，例如id =输入框中的值。但是，当执行代码时，我得到一个空集“ []”，尽管已填充数据库并且该数据库与我之前定义的其他函数一起正常显示，但它仍跳至if语句，该对话框为我提供了一个消息框。我的代码有错误吗？还是我在这里做错了什么？

预先感谢：）

看看代码：

def sp_patient():
        #Creating window
        sp_pat = Toplevel(update)
        sp_pat.title('Choose Patient')

        def search():
            #Assigning variable to .get()
            a = drops.get()

            if a == 'id' or a == 'emirate_id' or a == 'email_adress' or a == 'gender' or a == 'DOB' or a == 'blood_grp' or a == 'COVID_test':

                #Establishing connection
                con = mysql.connect(host='', user='',
                                    password='', database='')
                # Making SQL command
                sql_command = "SELECT * FROM patient_infos where %s = %s ;"
                values = a , e_1.get()
                c = con.cursor()
                c.execute(sql_command, values)

                # Executing and saving SQL command
                records = c.fetchall()
                print(records)
                if records == []:
                    messagebox.showinfo('Does not exist!','Sorry such patient does not exist')
                else:
                    #Creating window
                    result_win = Toplevel(sp_pat)
                    result_win.title('Search result')
                    index=0
                    for index,x in enumerate(records):
                        num=0
                        for y in x:
                            lookup_label = Label(result_win,text=y)
                            lookup_label.grid(row=index+1,column=num)
                            num += 1
                    #Closing connection
                    con.close()

                    #Creating column header and exit button
                    l_1 = Label(result_win,text='ID',font=font_text)
                    l_2 = Label(result_win,text='Full Name',font=font_text)
                    l_3 = Label(result_win,text='Phone no.',font=font_text)
                    l_4 = Label(result_win,text='Emirates ID',font=font_text)
                    l_5 = Label(result_win,text='Email addr.',font=font_text)
                    l_6 = Label(result_win,text='Gender',font=font_text)
                    l_7 = Label(result_win,text='DOB',font=font_text)
                    l_8 = Label(result_win,text='Nationality',font=font_text)
                    l_9 = Label(result_win,text='Blood group',font=font_text)
                    l_10 = Label(result_win,text='COVID test',font=font_text)
                    l_11 = Label(result_win,text='Emergency no.',font=font_text)
                    btn_ext = Button(result_win,text='Exit',font=font_text,command=result_win.destroy,borderwidth=2,fg='#eb4d4b')

                    #Placing it in screen
                    l_1.grid(row=0,column=0,padx=20)
                    l_2.grid(row=0,column=1,padx=20)
                    l_3.grid(row=0,column=2,padx=20)
                    l_4.grid(row=0,column=3,padx=20)
                    l_5.grid(row=0,column=4,padx=20)
                    l_6.grid(row=0,column=5,padx=20)
                    l_7.grid(row=0,column=6,padx=20)
                    l_8.grid(row=0,column=7,padx=20)
                    l_9.grid(row=0,column=8,padx=20)
                    l_10.grid(row=0,column=9,padx=20)
                    l_11.grid(row=0,column=10,padx=20)
                    btn_ext.grid(row=index+2,columnspan=11,ipadx=240,sticky=E+W)

Answer 1

您不能像这样将列名传递给查询。
您必须分两个步骤进行操作：

进行字符串替换，
仅将值传递给查询

                # Making SQL command
                sql_command = "SELECT * FROM patient_infos where {} = %s;"
                c = con.cursor()
                sql_command = sql_command.format(a)
                c.execute(sql_command, (e_1.get(),))

python mysql查询未显示正确结果

1 个答案: