Python & MySQL connector: AttributeError: 'CMySQLCursor' object has no attribute 'next'
Python & MySQL connector: AttributeError: 'CMySQLCursor' object has no attribute 'next'
- 我 运行宁 Ubuntu 18.04。
- 我正在使用 mysql-connector-python 将 Python 连接到 MySQL。
- 我正在使用 Python 3.6.7，并且已经安装了 mysql-connector-python.
- 我已经安装了mysql-connector-python-py3_8.0.13-1ubuntu18.10_all.deb.
当 运行 设置我的 Python 脚本时，mysql.connector 模块似乎正确加载，但脚本在遇到 cursor.next() 时失败并出现以下回溯错误：
AttributeError: 'CMySQLCursor' 对象没有属性 'next'
有趣的是，当我 运行 使用 Python 2.7.
时，相同的 python 脚本运行完美
import mysql.connector
import reddit_constants as rc
import logging
class MysqlManager:
def __init__(self, database, username, password, logger):
self.username = username
self.password = password
self.database = database
self.logger = logger
def __enter__(self):
try:
self.create_db()
self.conn = mysql.connector.connect(
user=self.username,
passwd=self.password,
auth_plugin='mysql_native_password',
database=self.database
)
if self.conn.is_connected():
self.logger.info('Connected to reddit database')
return self
except:
self.logger.error('Error: Could not connect to reddit database')
self.conn.close()
def __exit__(self, exc_type, exc_val, exc_tb):
self.conn.close()
def create_db(self):
mydb = mysql.connector.connect(
user=self.username,
passwd=self.password,
auth_plugin='mysql_native_password'
)
cursor = mydb.cursor()
cursor.execute("CREATE DATABASE IF NOT EXISTS " + self.database)
mydb.close()
def create_tables(self):
if not self.conn.is_connected():
self.logger.Error('Error in MySqlManager: You must initialize the connection to MySql')
return
cursor = self.conn.cursor()
cursor.execute("""
CREATE TABLE IF NOT EXISTS subreddit
(
subreddit_id INT AUTO_INCREMENT,
subreddit_name VARCHAR(30) NOT NULL UNIQUE,
subscriptions INT,
PRIMARY KEY (subreddit_id)
)
""")
cursor.execute("""
CREATE TABLE IF NOT EXISTS post (
post_id INT AUTO_INCREMENT,
subreddit_id INT NOT NULL,
post_title VARCHAR(500) NOT NULL,
post_ref VARCHAR(2084),
comments_ref VARCHAR(2084),
username VARCHAR(30),
created_time DATETIME NOT NULL,
PRIMARY KEY (post_id),
FOREIGN KEY (subreddit_id) REFERENCES subreddit(subreddit_id),
CONSTRAINT UC_post UNIQUE(subreddit_id, post_title, username, created_time)
)
""")
cursor.execute("""
CREATE TABLE IF NOT EXISTS post_history (
post_history_id INT AUTO_INCREMENT,
post_id INT,
votes INT,
ranks INT,
updated_time DATETIME,
PRIMARY KEY (post_history_id),
FOREIGN KEY (post_id) references post(post_id)
)
""")
cursor.execute("""
CREATE TABLE IF NOT EXISTS comment
(
comment_id INT AUTO_INCREMENT,
post_id INT NOT NULL,
subreddit_id INT NOT NULL,
username VARCHAR(30) NOT NULL,
created_time DATETIME NOT NULL,
PRIMARY KEY (comment_id),
FOREIGN KEY (subreddit_id) REFERENCES subreddit(subreddit_id),
FOREIGN KEY (post_id) REFERENCES post(post_id),
CONSTRAINT UC_comment UNIQUE(subreddit_id, post_id, username, created_time)
)
""")
cursor.execute("""
CREATE TABLE IF NOT EXISTS comment_history
(
comment_history_id INT AUTO_INCREMENT,
comment_id INT,
message TEXT,
votes INT,
updated_time DATETIME,
PRIMARY KEY (comment_history_id),
FOREIGN KEY (comment_id) references comment(comment_id)
)
""")
cursor.execute("""
CREATE TABLE IF NOT EXISTS youtube_info
(
youtube_info_id INT AUTO_INCREMENT,
post_id INT,
video_title TEXT,
publish_date DATETIME,
view_count INT,
like_count INT,
dislike_count INT,
comment_count INT,
PRIMARY KEY (youtube_info_id),
FOREIGN KEY (post_id) REFERENCES post(post_id),
CONSTRAINT UC_youtube_info UNIQUE(post_id)
)
""")
def insert_subreddits(self, posts):
if not self.conn.is_connected():
self.logger.Error('Error in MySqlManager: You must initialize the connection to MySql')
return
cursor = self.conn.cursor()
for post in posts:
values = (post[rc.SUBREDDIT_KEY], None)
query = """
INSERT IGNORE INTO subreddit (subreddit_name, subscriptions)
VALUES(%s, %s)
"""
cursor.execute(query, values)
self.conn.commit()
new_id = cursor.lastrowid
if new_id == 0:
id_query = "SELECT subreddit_id FROM subreddit WHERE subreddit_name = %s"
id_values = (post[rc.SUBREDDIT_KEY],)
cursor.execute(id_query, id_values)
new_id = cursor.next()[0]
post[rc.SUBREDDIT_ID] = new_id
self.logger.info(' - Inserted subreddits from page successfully')
def insert_posts(self, posts):
if not self.conn.is_connected():
self.logger.Error('Error in MySqlManager: You must initialize the connection to MySql')
return
cursor = self.conn.cursor()
for post in posts:
post_values = (post[rc.SUBREDDIT_ID],
post[rc.POST_TITLE_KEY],
post[rc.POST_REF_KEY],
post[rc.COMMENTS_REF_KEY],
post[rc.USER_KEY],
post[rc.CREATED_TIMESTAMP_KEY])
post_query = """
INSERT IGNORE INTO post (subreddit_id, post_title, post_ref,
comments_ref, username, created_time)
VALUES (%s, %s, %s, %s, %s, %s)
"""
cursor.execute(post_query, post_values)
self.conn.commit()
new_id = cursor.lastrowid
if new_id == 0:
id_query = """
SELECT post_id
FROM post
WHERE subreddit_id = %s
AND post_title = %s
AND username = %s
AND created_time = %s
"""
id_values = (post[rc.SUBREDDIT_ID],
post[rc.POST_TITLE_KEY],
post[rc.USER_KEY],
post[rc.CREATED_TIMESTAMP_KEY])
cursor.execute(id_query, id_values)
new_id = cursor.next()[0]
post[rc.POST_ID] = new_id
post_history_values = (post[rc.POST_ID],
post[rc.VOTE_KEY],
post[rc.RANK_KEY])
post_history_query = """
INSERT INTO post_history (post_id, votes, ranks, updated_time)
(SELECT %s, %s, %s, NOW())
"""
cursor.execute(post_history_query, post_history_values)
self.conn.commit()
self.logger.info(' - Inserted posts from page successfully')
def insert_video_info(self, video_info):
if not self.conn.is_connected():
self.logger.Error('MySqlManager: You must initialize the connection to MySql')
return
cursor = self.conn.cursor()
video_info_values = (video_info[rc.POST_ID],
video_info[rc.YOUTUBE_TITLE_KEY],
video_info[rc.YOUTUBE_PUBLISHED_KEY],
video_info[rc.YOUTUBE_VIEW_COUNT_KEY],
video_info[rc.YOUTUBE_LIKE_KEY],
video_info[rc.YOUTUBE_DISLIKE_KEY],
video_info[rc.YOUTUBE_COMMENT_KEY])
video_info_query = """
INSERT IGNORE INTO youtube_info (post_id,
video_title,
publish_date,
view_count,
like_count,
dislike_count,
comment_count)
VALUES (%s, %s, %s, %s, %s, %s, %s)
"""
cursor.execute(video_info_query, video_info_values)
self.conn.commit()
def insert_comments(self, comments, post):
if not self.conn.is_connected():
self.logger.Error('Error in MySqlManager: You must initialize the connection to MySql')
return
cursor = self.conn.cursor()
for comment in comments:
comment_values = (post[rc.POST_ID],
post[rc.SUBREDDIT_ID],
comment[rc.USER_KEY],
comment[rc.CREATED_TIMESTAMP_KEY])
comment_query = """
INSERT IGNORE INTO comment (post_id, subreddit_id, username, created_time)
VALUES (%s, %s, %s, %s)
"""
cursor.execute(comment_query, comment_values)
self.conn.commit()
new_id = cursor.lastrowid
if new_id == 0:
id_query = """
SELECT comment_id
FROM comment
WHERE post_id = %s
AND username = %s
AND created_time = %s
"""
id_values = (post[rc.POST_ID],
comment[rc.USER_KEY],
comment[rc.CREATED_TIMESTAMP_KEY])
cursor.execute(id_query, id_values)
new_id = cursor.next()[0]
comment[rc.COMMENT_ID] = new_id
comment_history_values = (comment[rc.COMMENT_ID],
comment[rc.VOTE_KEY],
comment[rc.MESSAGE_KEY])
comment_history_query = """
INSERT INTO comment_history (comment_id, votes, message, updated_time)
(SELECT %s, %s, %s, NOW())
"""
cursor.execute(comment_history_query, comment_history_values)
self.conn.commit()
self.logger.info('Inserted comments from {} post successfully'.format(post[rc.POST_REF_KEY]))
def mysql_test_suite():
import csv
with MysqlManager(rc.DATABASE_NAME,
rc.DB_USERNAME,
rc.DB_PASSWORD,
logging.getLogger('test')) as mysql_test:
with open("testfiles/posts.csv", "r") as f:
reader = csv.DictReader(f)
posts = list(reader)
mysql_test.insert_subreddits(posts)
mysql_test.insert_posts(posts)
for post_test in posts:
assert post_test[rc.SUBREDDIT_ID] > 0
assert post_test[rc.POST_ID] > 0
with open("testfiles/comments.csv", "r") as f:
reader = csv.DictReader(f)
comments = list(reader)
mysql_test.insert_comments(comments, posts[0])
for comment in comments:
assert comment[rc.COMMENT_ID] > 0
if __name__ == "__main__":
mysql_test_suite()
print("All mysql tests ran successfully")
正如 roganjosh 提到的，next() 不是一个属性。我改用了 fetchone()。
next() 似乎在 mysql-connector-python 中不可用
但它在 mysql-连接器库中可用。
尝试
pip uninstall mysql-connector-python
pip install mysql-connector
- 我 运行宁 Ubuntu 18.04。
- 我正在使用 mysql-connector-python 将 Python 连接到 MySQL。
- 我正在使用 Python 3.6.7，并且已经安装了 mysql-connector-python.
- 我已经安装了mysql-connector-python-py3_8.0.13-1ubuntu18.10_all.deb.
当 运行 设置我的 Python 脚本时，mysql.connector 模块似乎正确加载，但脚本在遇到 cursor.next() 时失败并出现以下回溯错误：
AttributeError: 'CMySQLCursor' 对象没有属性 'next'
有趣的是，当我 运行 使用 Python 2.7.
时，相同的 python 脚本运行完美import mysql.connector
import reddit_constants as rc
import logging
class MysqlManager:
def __init__(self, database, username, password, logger):
self.username = username
self.password = password
self.database = database
self.logger = logger
def __enter__(self):
try:
self.create_db()
self.conn = mysql.connector.connect(
user=self.username,
passwd=self.password,
auth_plugin='mysql_native_password',
database=self.database
)
if self.conn.is_connected():
self.logger.info('Connected to reddit database')
return self
except:
self.logger.error('Error: Could not connect to reddit database')
self.conn.close()
def __exit__(self, exc_type, exc_val, exc_tb):
self.conn.close()
def create_db(self):
mydb = mysql.connector.connect(
user=self.username,
passwd=self.password,
auth_plugin='mysql_native_password'
)
cursor = mydb.cursor()
cursor.execute("CREATE DATABASE IF NOT EXISTS " + self.database)
mydb.close()
def create_tables(self):
if not self.conn.is_connected():
self.logger.Error('Error in MySqlManager: You must initialize the connection to MySql')
return
cursor = self.conn.cursor()
cursor.execute("""
CREATE TABLE IF NOT EXISTS subreddit
(
subreddit_id INT AUTO_INCREMENT,
subreddit_name VARCHAR(30) NOT NULL UNIQUE,
subscriptions INT,
PRIMARY KEY (subreddit_id)
)
""")
cursor.execute("""
CREATE TABLE IF NOT EXISTS post (
post_id INT AUTO_INCREMENT,
subreddit_id INT NOT NULL,
post_title VARCHAR(500) NOT NULL,
post_ref VARCHAR(2084),
comments_ref VARCHAR(2084),
username VARCHAR(30),
created_time DATETIME NOT NULL,
PRIMARY KEY (post_id),
FOREIGN KEY (subreddit_id) REFERENCES subreddit(subreddit_id),
CONSTRAINT UC_post UNIQUE(subreddit_id, post_title, username, created_time)
)
""")
cursor.execute("""
CREATE TABLE IF NOT EXISTS post_history (
post_history_id INT AUTO_INCREMENT,
post_id INT,
votes INT,
ranks INT,
updated_time DATETIME,
PRIMARY KEY (post_history_id),
FOREIGN KEY (post_id) references post(post_id)
)
""")
cursor.execute("""
CREATE TABLE IF NOT EXISTS comment
(
comment_id INT AUTO_INCREMENT,
post_id INT NOT NULL,
subreddit_id INT NOT NULL,
username VARCHAR(30) NOT NULL,
created_time DATETIME NOT NULL,
PRIMARY KEY (comment_id),
FOREIGN KEY (subreddit_id) REFERENCES subreddit(subreddit_id),
FOREIGN KEY (post_id) REFERENCES post(post_id),
CONSTRAINT UC_comment UNIQUE(subreddit_id, post_id, username, created_time)
)
""")
cursor.execute("""
CREATE TABLE IF NOT EXISTS comment_history
(
comment_history_id INT AUTO_INCREMENT,
comment_id INT,
message TEXT,
votes INT,
updated_time DATETIME,
PRIMARY KEY (comment_history_id),
FOREIGN KEY (comment_id) references comment(comment_id)
)
""")
cursor.execute("""
CREATE TABLE IF NOT EXISTS youtube_info
(
youtube_info_id INT AUTO_INCREMENT,
post_id INT,
video_title TEXT,
publish_date DATETIME,
view_count INT,
like_count INT,
dislike_count INT,
comment_count INT,
PRIMARY KEY (youtube_info_id),
FOREIGN KEY (post_id) REFERENCES post(post_id),
CONSTRAINT UC_youtube_info UNIQUE(post_id)
)
""")
def insert_subreddits(self, posts):
if not self.conn.is_connected():
self.logger.Error('Error in MySqlManager: You must initialize the connection to MySql')
return
cursor = self.conn.cursor()
for post in posts:
values = (post[rc.SUBREDDIT_KEY], None)
query = """
INSERT IGNORE INTO subreddit (subreddit_name, subscriptions)
VALUES(%s, %s)
"""
cursor.execute(query, values)
self.conn.commit()
new_id = cursor.lastrowid
if new_id == 0:
id_query = "SELECT subreddit_id FROM subreddit WHERE subreddit_name = %s"
id_values = (post[rc.SUBREDDIT_KEY],)
cursor.execute(id_query, id_values)
new_id = cursor.next()[0]
post[rc.SUBREDDIT_ID] = new_id
self.logger.info(' - Inserted subreddits from page successfully')
def insert_posts(self, posts):
if not self.conn.is_connected():
self.logger.Error('Error in MySqlManager: You must initialize the connection to MySql')
return
cursor = self.conn.cursor()
for post in posts:
post_values = (post[rc.SUBREDDIT_ID],
post[rc.POST_TITLE_KEY],
post[rc.POST_REF_KEY],
post[rc.COMMENTS_REF_KEY],
post[rc.USER_KEY],
post[rc.CREATED_TIMESTAMP_KEY])
post_query = """
INSERT IGNORE INTO post (subreddit_id, post_title, post_ref,
comments_ref, username, created_time)
VALUES (%s, %s, %s, %s, %s, %s)
"""
cursor.execute(post_query, post_values)
self.conn.commit()
new_id = cursor.lastrowid
if new_id == 0:
id_query = """
SELECT post_id
FROM post
WHERE subreddit_id = %s
AND post_title = %s
AND username = %s
AND created_time = %s
"""
id_values = (post[rc.SUBREDDIT_ID],
post[rc.POST_TITLE_KEY],
post[rc.USER_KEY],
post[rc.CREATED_TIMESTAMP_KEY])
cursor.execute(id_query, id_values)
new_id = cursor.next()[0]
post[rc.POST_ID] = new_id
post_history_values = (post[rc.POST_ID],
post[rc.VOTE_KEY],
post[rc.RANK_KEY])
post_history_query = """
INSERT INTO post_history (post_id, votes, ranks, updated_time)
(SELECT %s, %s, %s, NOW())
"""
cursor.execute(post_history_query, post_history_values)
self.conn.commit()
self.logger.info(' - Inserted posts from page successfully')
def insert_video_info(self, video_info):
if not self.conn.is_connected():
self.logger.Error('MySqlManager: You must initialize the connection to MySql')
return
cursor = self.conn.cursor()
video_info_values = (video_info[rc.POST_ID],
video_info[rc.YOUTUBE_TITLE_KEY],
video_info[rc.YOUTUBE_PUBLISHED_KEY],
video_info[rc.YOUTUBE_VIEW_COUNT_KEY],
video_info[rc.YOUTUBE_LIKE_KEY],
video_info[rc.YOUTUBE_DISLIKE_KEY],
video_info[rc.YOUTUBE_COMMENT_KEY])
video_info_query = """
INSERT IGNORE INTO youtube_info (post_id,
video_title,
publish_date,
view_count,
like_count,
dislike_count,
comment_count)
VALUES (%s, %s, %s, %s, %s, %s, %s)
"""
cursor.execute(video_info_query, video_info_values)
self.conn.commit()
def insert_comments(self, comments, post):
if not self.conn.is_connected():
self.logger.Error('Error in MySqlManager: You must initialize the connection to MySql')
return
cursor = self.conn.cursor()
for comment in comments:
comment_values = (post[rc.POST_ID],
post[rc.SUBREDDIT_ID],
comment[rc.USER_KEY],
comment[rc.CREATED_TIMESTAMP_KEY])
comment_query = """
INSERT IGNORE INTO comment (post_id, subreddit_id, username, created_time)
VALUES (%s, %s, %s, %s)
"""
cursor.execute(comment_query, comment_values)
self.conn.commit()
new_id = cursor.lastrowid
if new_id == 0:
id_query = """
SELECT comment_id
FROM comment
WHERE post_id = %s
AND username = %s
AND created_time = %s
"""
id_values = (post[rc.POST_ID],
comment[rc.USER_KEY],
comment[rc.CREATED_TIMESTAMP_KEY])
cursor.execute(id_query, id_values)
new_id = cursor.next()[0]
comment[rc.COMMENT_ID] = new_id
comment_history_values = (comment[rc.COMMENT_ID],
comment[rc.VOTE_KEY],
comment[rc.MESSAGE_KEY])
comment_history_query = """
INSERT INTO comment_history (comment_id, votes, message, updated_time)
(SELECT %s, %s, %s, NOW())
"""
cursor.execute(comment_history_query, comment_history_values)
self.conn.commit()
self.logger.info('Inserted comments from {} post successfully'.format(post[rc.POST_REF_KEY]))
def mysql_test_suite():
import csv
with MysqlManager(rc.DATABASE_NAME,
rc.DB_USERNAME,
rc.DB_PASSWORD,
logging.getLogger('test')) as mysql_test:
with open("testfiles/posts.csv", "r") as f:
reader = csv.DictReader(f)
posts = list(reader)
mysql_test.insert_subreddits(posts)
mysql_test.insert_posts(posts)
for post_test in posts:
assert post_test[rc.SUBREDDIT_ID] > 0
assert post_test[rc.POST_ID] > 0
with open("testfiles/comments.csv", "r") as f:
reader = csv.DictReader(f)
comments = list(reader)
mysql_test.insert_comments(comments, posts[0])
for comment in comments:
assert comment[rc.COMMENT_ID] > 0
if __name__ == "__main__":
mysql_test_suite()
print("All mysql tests ran successfully")
正如 roganjosh 提到的，next() 不是一个属性。我改用了 fetchone()。
next() 似乎在 mysql-connector-python 中不可用 但它在 mysql-连接器库中可用。 尝试
pip uninstall mysql-connector-python
pip install mysql-connector