So I have got the average salaries from my server, and store into a python variable and I want to know is that possible to use this variable in the later SQL common in python? and I got the avg is '51777'
connection = pymysql.connect (host = "...",
user = "...",
passwd = "...",
db = "...")
cursor = connection.cursor()
# select employeeID from employees table using where, group by, and order by
cursor.execute("\
select title, avg(salaries) \
from employees group by title;")
x = cursor.fetchall()
print x
#store the value calculated from the table
cursor.execute("\
select avg(salaries) \
from employees;")
y = cursor.fetchall()
print y
z = y[0]
z = int(z[0])
print z
#using the variable into sql command
cursor.execute("select employeeID \
from employees where salaries > %s)", (z))
a = cursor.fetchall()
print a
cursor.close()
connection.close()
and the code
#using the variable into sql command
cursor.execute("select employeeID \
from employees where salaries > %s)", (z))
doesn't work and I am not sure what to do next
Sorry I forgot to contain the error:
ProgrammingErrorTraceback (most recent call last)
W:\My Documents\calsses\2018 spring\MGMT 590\project\other queries.py in <module>()
38 #using the variable into sql command
39 cursor.execute("select employeeID \
---> 40 from employees where salaries > %s)", (z,))
41
42 a = cursor.fetchall()
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\cursors.py in execute(self, query, args)
164 query = self.mogrify(query, args)
165
--> 166 result = self._query(query)
167 self._executed = query
168 return result
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\cursors.py in _query(self, q)
320 conn = self._get_db()
321 self._last_executed = q
--> 322 conn.query(q)
323 self._do_get_result()
324 return self.rowcount
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\connections.py in query(self, sql, unbuffered)
833 sql = sql.encode(self.encoding, 'surrogateescape')
834 self._execute_command(COMMAND.COM_QUERY, sql)
--> 835 self._affected_rows = self._read_query_result(unbuffered=unbuffered)
836 return self._affected_rows
837
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\connections.py in _read_query_result(self, unbuffered)
1017 else:
1018 result = MySQLResult(self)
-> 1019 result.read()
1020 self._result = result
1021 if result.server_status is not None:
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\connections.py in read(self)
1300 def read(self):
1301 try:
-> 1302 first_packet = self.connection._read_packet()
1303
1304 if first_packet.is_ok_packet():
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\connections.py in _read_packet(self, packet_type)
979
980 packet = packet_type(buff, self.encoding)
--> 981 packet.check_error()
982 return packet
983
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\connections.py in check_error(self)
391 errno = self.read_uint16()
392 if DEBUG: print("errno =", errno)
--> 393 err.raise_mysql_exception(self._data)
394
395 def dump(self):
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\err.py in raise_mysql_exception(data)
105 errval = data[3:].decode('utf-8', 'replace')
106 errorclass = error_map.get(errno, InternalError)
--> 107 raise errorclass(errno, errval)
ProgrammingError: (1064, u"You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1")
After I add triple quotes like this:
cursor.execute('''select employeeID
from employees where salaries > %s)''', (z,))
and still doesn't work Error:
ProgrammingErrorTraceback (most recent call last)
W:\My Documents\calsses\2018 spring\MGMT 590\project\other queries.py in <module>()
38 #using the variable into sql command
39 cursor.execute('''select employeeID
---> 40 from employees where salaries > %s)''', (z,))
41
42 a = cursor.fetchall()
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\cursors.py in execute(self, query, args)
164 query = self.mogrify(query, args)
165
--> 166 result = self._query(query)
167 self._executed = query
168 return result
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\cursors.py in _query(self, q)
320 conn = self._get_db()
321 self._last_executed = q
--> 322 conn.query(q)
323 self._do_get_result()
324 return self.rowcount
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\connections.py in query(self, sql, unbuffered)
833 sql = sql.encode(self.encoding, 'surrogateescape')
834 self._execute_command(COMMAND.COM_QUERY, sql)
--> 835 self._affected_rows = self._read_query_result(unbuffered=unbuffered)
836 return self._affected_rows
837
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\connections.py in _read_query_result(self, unbuffered)
1017 else:
1018 result = MySQLResult(self)
-> 1019 result.read()
1020 self._result = result
1021 if result.server_status is not None:
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\connections.py in read(self)
1300 def read(self):
1301 try:
-> 1302 first_packet = self.connection._read_packet()
1303
1304 if first_packet.is_ok_packet():
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\connections.py in _read_packet(self, packet_type)
979
980 packet = packet_type(buff, self.encoding)
--> 981 packet.check_error()
982 return packet
983
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\connections.py in check_error(self)
391 errno = self.read_uint16()
392 if DEBUG: print("errno =", errno)
--> 393 err.raise_mysql_exception(self._data)
394
395 def dump(self):
C:\Program Files\Enthought\Canopy\edm\envs\User\lib\site-packages\pymysql\err.py in raise_mysql_exception(data)
105 errval = data[3:].decode('utf-8', 'replace')
106 errorclass = error_map.get(errno, InternalError)
--> 107 raise errorclass(errno, errval)
ProgrammingError: (1064, u"You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 2")
答案 0 :(得分：0)
因此我有两种方法可以在python 2.7中解决这个问题，我认为最好分享这个解决方案。所以它失败的主要原因是我没有将变量转换为字符串，为了在python中使用SQL命令，我们必须转换SQL命令。所以有两种方法可以解决这个问题：
#1
cursor.execute('''select employeeID,FirstName, LastName
from employees where salaries > ''' + str(z) + ''';''')
#2
cursor.execute('''select employeeID,FirstName, LastName
from employees
where salaries > %s ;''' %(z))