插入mysql数据库，pymysql无法插入

Question

我正在尝试将虚拟数据插入 mysql 数据库。

数据库结构如下：

database name: messaround database table name: test

表结构：

id (Primary key, auto increment) path (varchar(254))

UPDATED 2 方法和错误。 我有一种方法可以尝试通过以下方式插入：

def insert_into_db(dbcursor, table, *cols, **vals):
    try:
        query = "INSERT INTO {} ({}) VALUES ('{}')".format(table, ",".join(cols),  "'),('".join(vals))  
        print(query)
        dbcursor.execute(query)
        dbcursor.commit()
        print("inserted!")
    except pymysql.Error as exc:
        print("error inserting...\n {}".format(exc))

connection=conn_db()        
insertstmt=insert_into_db(connection, table='test', cols=['path'], vals=['test.com/test2'])

但是，这是失败的说法：

INSERT INTO test () VALUES ('vals'),('cols')
error inserting...
 (1136, "Column count doesn't match value count at row 1")

你能帮忙吗？

谢谢。

Answer 1

如果您使用您的代码：

def insert_into_db(dbcursor, table, *cols, **vals):
    query = "INSERT INTO {} ({}) VALUES ({})".format(table,",".join(cols), ",".join(vals))
    print(query)

insert_into_db('cursor_here', 'table_here', 'name', 'city', name_person='diego', city_person='Sao Paulo')

Python 返回：

INSERT INTO table_here (name,city) VALUES (name_person,city_person)

现在和另一个：

def new_insert_into_db(dbcursor, table, *cols, **vals):
    vals2 = ''
    for first_part, second_part in vals.items():
        vals2 += '\'' + second_part + '\','
    vals2 = vals2[:-1]
    query = "INSERT INTO {} ({}) VALUES ({})".format(table,",".join(cols), vals2)
    print(query)

new_insert_into_db('cursor_here', 'table_here', 'name', 'city', name_person='diego', city_person='Sao Paulo')

Python 将返回正确的 SQL：

INSERT INTO table_here (name,city) VALUES ('diego','Sao Paulo')

Answer 2

通常在 Python 中，您将参数化查询传递给 DB 驱动程序。见this example in PyMySQL's documentation；它使用占位符构造 INSERT 查询，然后调用 cursor.execute() 传递查询和实际值的元组。

使用参数化查询也是recommended for security purposes，因为它可以击败许多常见的SQL注入攻击。

Answer 3

你应该打印你生成的 sql 语句，这样更容易看出哪里出了问题。

但我猜你需要在 ",".join(vals) 的字符串值周围加上引号 '（以防有字符串值。
所以你的代码正在生成

insert into test (path,) values (test.com/test2,);

但它应该产生

insert into test (`path`) values ('test.com/test2');

否则请尝试https://github.com/markuman/MariaSQL/，这使得使用 pymysql 将数据插入 MariaDB/MySQL 变得超级容易。

Answer 4

如下更改您的查询

query = "INSERT INTO {} ({}) VALUES ('{}')".format(table, ",".join(cols),  "'),('".join(vals))

当你使用连接时，变量应该是一个列表而不是一个字符串

table = 'test'
cols = ['path']
vals = ['test.com/test2', 'another.com/anothertest']


print(query)

"INSERT INTO test (path) VALUES ('test.com/test2'),('another.com/anothertest')"

更新：

def insert_into_db(dbconnection=None, table='', cols=None, vals=None):
    mycursor = dbconnection.cursor()
    if not (dbconnection and table and cols and vals):
        print('Must need all values')
        quit()
    try:
        query = "INSERT INTO {} ({}) VALUES ('{}')".format(table, ",".join(cols),  "'),('".join(vals))
        mycursor.execute(query)
        dbconnection.commit()
        print("inserted!")
    except pymysql.Error as exc:
        print("error inserting...\n {}".format(exc))


connection=conn_db()        

insertstmt=insert_into_db(dbconnection=connection, table='test', cols=['path'], vals=['test.com/test2'])