错误 1064 (42000)：您的 SQL 语法错误...靠近“ ”

如何解决错误 1064 (42000)：您的 SQL 语法错误...靠近“ ”

我被困了几天，尝试了本网站上类似问题的大部分答案。

在开始之前，我想指出我通过 ssh 工作并且只能通过 nano 编辑代码（不是我的选择......）

我的问题如下：

我正在使用 MariaDB 沿相机温度存储树莓派 cpu 温度以绘制温度变化图。尝试在数据库中插入值时出错。

我在 cpu_tempDB 中有下表

await

在我的 python 代码中，我使用以下函数：

MariaDB [cpu_tempDB]> show columns from cpu_TEMP_TABLE;
+-------------+--------------+------+-----+---------------------+----------------+
| Field       | Type         | Null | Key | Default             | Extra          |
+-------------+--------------+------+-----+---------------------+----------------+
| ID          | bigint(20)   | NO   | PRI | NULL                | auto_increment |
| cpu_TEMP    | decimal(6,2) | NO   |     | NULL                |                |
| CREATED     | timestamp    | NO   |     | current_timestamp() |                |
| CAMERA_TEMP | decimal(6,2) | NO   |     | 0.00                |                |
+-------------+--------------+------+-----+---------------------+----------------+

我收到以下错误：

from gpiozero import cpuTemperature
import MysqL.connector as mariadb

# get cpu temperature in Celsius
cpu = cpuTemperature()
cpu_temp = cpu.temperature

# get Camera temperature in Celsius
tempfile = open("/home/pi/allsky/temperature.txt","r")
cam_temp = tempfile.read().rstrip()

# make a new mariaDB entry and retrieve old values
try:
   # open connection
   mariadb_connection = mariadb.connect(host= "localhost",user="pi",password="--Sensored--",database="cpu_tempDB")
   cursor = mariadb_connection.cursor()
   # upload
   sql = "insert into cpu_TEMP_TABLE (cpu_TEMP,CAMERA_TEMP) values (%s,%s)"
   args = cpu_temp,float(cam_temp)
   cursor.execute(sql,args)
   mariadb_connection.commit()
   # fetch
   cursor.execute("select * from cpu_TEMP_TABLE where cpu_TEMP_TABLE.CREATED > DATE_SUB(Now(),INTERVAL 7 DAY")
   records = cursor.fetchall()
except mariadb.Error as e:
   print("Error writing cpu temp to mariaDB:",e)
finally:
   mariadb_connection.close()
   cursor.close()
# store data in lists
time_list = []
cpu_temp_list = []

for row in records:
  cpu_temp_list.append(row[1])
  time_list.append(row[2])

# declare date formatter for plot
myFmt = mdates.DateFormatter('%H:%M')

# generate plot
mpl.use('Agg')


plt.plot(time_list,cpu_temp_list,'b-')
plt.xlabel('Time')
plt.ylabel('cpu Temperature [°C]')
plt.title('cpu Temperature evolution over the last 48 hours')
plt.gca().xaxis.set_major_formatter(myFmt)

# save plot
plt.savefig('cpu_temp.png')

编辑： 我在错误之前添加了一个打印（sql，args），这是控制台打印

Error writing cpu temp to mariaDB: 1064 (42000): You have an error in your sql Syntax; check the manual that corresponds to your MariaDB server version for the right Syntax to use near '' at line 1
Traceback (most recent call last):
  File "cpu_temp.py",line 45,in <module>
    for row in records:
NameError: name 'records' is not defined

编辑 2：添加了其余的代码，因为你们中的一些人提到错误警告显示在显示的代码之外

编辑 3：从 0 重新启动，现在它可以工作了......不幸的是，我无法删除这篇文章

解决方法

您需要将参数放入元组中：

sql = "insert into CPU_TEMP_TABLE (CPU_TEMP,CAMERA_TEMP) values (%s,%s)"
args = (cpu_temp,float(cam_temp),)
cursor.execute(sql,args)

或者就地构造一个字符串：

sql = "insert into CPU_TEMP_TABLE (CPU_TEMP,CAMERA_TEMP)
    values (%s,%s)" % (cpu_temp,)
cursor.execute(sql)

,

问题出在这个查询中：

select *
from CPU_TEMP_TABLE 
where CPU_TEMP_TABLE.CREATED > DATE_SUB(NOW(),INTERVAL 7 DAY

DATE_SUB 函数的括号没有闭合。解决方法是添加右括号：

select * 
from CPU_TEMP_TABLE 
where CPU_TEMP_TABLE.CREATED > DATE_SUB(NOW(),INTERVAL 7 DAY)

不幸的是，错误信息如此高深莫测...

,

我从头开始重写了所有内容并定义了 2 个不同的游标，它有点奏效。

感谢您的帮助

这是工作代码：

from gpiozero import CPUTemperature
from time import sleep,strftime,time
import mysql.connector as mariadb
import matplotlib.pyplot as plt
import matplotlib as mpl
import datetime
import matplotlib.dates as mdates

# get CPU temperature in Celsius
cpu = CPUTemperature()
cpu_temp = cpu.temperature

# get Camera temperature in Celsius
tempfile = open("/home/pi/allsky/temperature.txt","r")
cam_temp = tempfile.read().rstrip()

# make a new mariaDB entry and retrieve old values
try:
   mariadb_connection = mariadb.connect(user='pi',password='...',database='cpu_tempDB')
   cursor1 = mariadb_connection.cursor()
   sql1 = "insert into CPU_TEMP_TABLE (CPU_TEMP,%s)"
   args = (cpu_temp,float(cam_temp))
   cursor1.execute(sql1,args)
   mariadb_connection.commit()

   cursor2 = mariadb_connection.cursor()
   sql2 = "select * from CPU_TEMP_TABLE where CREATED > DATE_SUB(NOW(),INTERVAL 5 DAY)"
   cursor2.execute(sql2)
   records = cursor2.fetchall()
except mariadb.Error as e:
   print("Error mariaDB:",e)
finally:
   mariadb_connection.close()
   cursor1.close()
   cursor2.close()
# store data in lists
time_list = []
cpu_temp_list = []
cam_temp_list = []

for row in records:
  cpu_temp_list.append(row[1])
  time_list.append(row[2])
  cam_temp_list.append(row[3])

# declare date formatter for plot
myFmt = mdates.DateFormatter('%H:%M')

# generate plot
mpl.use('Agg')


plt.plot(time_list,cpu_temp_list,'b-')
plt.xlabel('Time')
plt.ylabel('CPU Temperature [°C]')
plt.title('CPU Temperature evolution over the last 48 hours')
plt.gca().xaxis.set_major_formatter(myFmt)

# save plot
plt.savefig('cpu_temp.png')