通过python操作mysql数据库

1. ubuntu下安装mysql-server

在ubuntu16.04下通过命令sudo apt install mysql-server安装mysql服务器。然后为了让python练级数据库

然后通过pip工具安装mysql-connector。即在命令行界面输入：pip install mysql-connector。

2. 连接数据库

def test_connect():
config = {
"host": "127.0.0.1",
"user": "root",
"password": "******",
"port": 3306,
"database": "test",
"charset": "utf8",
}
try:
cnn = mysql.connector.connect(**config)
print("success connected!")
return cnn
except mysql.connector.Error as e:
print('connected failed {}!'.format(e))

3. 创建表

def create_table(_cnn):
'''
:param _cnn:连接器
:return:
建表语句中的名称均可以用``来括起来，注意此处不是单引号
'''
sql = 'CREATE TABLE students2' \
'(id INT(10) NOT NULL AUTO_INCREMENT,' \
'name VARCHAR(20) DEFAULT NULL,' \
'PRIMARY KEY(id))' \
'DEFAULT CHARSET=utf8'
cursor = _cnn.cursor()
try:
cursor.execute(sql)
except mysql.connector.Error as e:
print('created failed {}!'.format(e))

4. 插入数据

def insert_data(_cnn):
cursor = _cnn.cursor()
try:
# 直接字符串插入方式
sql_insert1 = 'insert into students(id, name) VALUES(2, "xie")'
cursor.execute(sql_insert1)

# 元组插入方式,此处%s是占位符不是格式化字符串所以id也对应%s
sql_insert2 = "insert into students(id, name) VALUES(%s, %s)"
datas = (11, "hello")
cursor.execute(sql_insert2, datas)

# 字典插入方式
sql_insert3 = "insert into students(id, name) VALUES(%(id)s, %(name)s)"
data_dic = {'id': 12,
'name': 'hi'}
cursor.execute(sql_insert3, data_dic)

#多次插入
stmt = "insert into students(id, name) VALUES (%s, %s)"
datas = [(5, 'many'),
(6, 'happy'),
(7, 'just a test')]
cursor.executemany(stmt, datas)

print('insert completed!')
except mysql.connector.Error as e:
print('inserted failed {}!'.format(e))
finally:
cursor.close()
# 此处的数据库引擎是Innodb,执行完后需要执行commit进行事务提交
_cnn.commit()
_cnn.close()

5. 查询操作

def query_data(_cnn):
cursor = _cnn.cursor()
try:
sql = 'select name from students where id=%s'
cursor.execute(sql, (2,))
for name in cursor:
print(name)
except mysql.connector.Error as e:
print('query failed {}!'.format(e))
finally:
cursor.close()
_cnn.close()

6. 删除操作

def delete_data(_cnn):
cursor = _cnn.cursor()
try:
sql = 'delete from students where id=%s'
cursor.execute(sql, (2,))
print('delete complete!')
except mysql.connector.Error as e:
print('deleted failed {}!'.format(e))
finally:
cursor.close()
_cnn.commit()
_cnn.close()