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不知道为什么在尝试使用 f 字符串运行 SQL UPDATE 查询时出现语法错误

百变鹏仔 1天前 #Python
文章标签 不知道为什么
问题内容

我正在尝试运行基本的 sql 查询来更新名为 bartonhill 的数据库中 schoolnum 的值,使用 f 字符串将值放入

import sqlite3name = [input('enter your firstname: ')]conn = sqlite3.connect('revision.db')c = conn.cursor()# create tablec.execute('''CREATE TABLE IF NOT EXISTS bartonHill (    firstName TEXT NOT NULL,    lastName TEXT NOT NULL,    schoolNum INTEGER NOT NULL PRIMARY KEY)''')conn.commit()c.execute("INSERT INTO bartonHill VALUES ('Ollie','Burgess','20314')")conn.commit()new_number = tuple[(int(input('enter your new school number')))]c.execute(f"UPDATE bartonHill set schoolNum = '{new_number}' WHERE firstName = '{name}'")conn.commitc.execute('SELECT lastName, schoolNum FROM bartonHill WHERE firstName = (?)',name)print(c.fetchall())

但是,如果我输入我的名字 ollie(作为 firsname 存在于数据库中),则运行此代码会出现错误“ sqlite3.operationalerror:near“ollie”:语法错误”

我尝试更改 name 和 new_number 的数据类型,但这仅更改了错误


正确答案


还有很多需要改进的地方。我只做了一些小改动,你可以进一步改进。始终插入元组。更改主键是可能的,但不是那么容易,谷歌一下。首次初始化值后请求新值。也请仔细阅读上面的评论!

import sqlite3conn = sqlite3.connect('revision.db')c = conn.cursor()# create tablec.execute('''create table if not exists bartonhill (    id integer primary key autoincrement,    schoolnum integer not null,    firstname text not null,    lastname text not null   )''')conn.commit()c.execute("insert into bartonhill (schoolnum,firstname,lastname) values (?,?,?); ", (20314, 'ollie','burgess'))conn.commit()# ask for changes herefirstname = input('enter your firstname: ')lastname = input('enter your lastname: ')new_number = int(input('enter your new school number: '))c.execute("update bartonhill set schoolnum = ? where firstname = ?;", (new_number, firstname))conn.commitc.execute("select * from bartonhill where firstname = ?;", (firstname,))print(c.fetchall())

输出:

>>> enter your firstname: ollie>>> enter your lastname: burgess>>> enter your new school number: 20000>>> [(1, 20000, 'ollie', 'burgess')]

或另一个选择:

c.execute("select schoolnum, lastname from bartonhill where firstname = ?;", (firstname,))print(c.fetchone())

仅给您特定值:

(20000, 'Burgess')