Question

我在Python上使用mysqlclient运行查询时遇到了麻烦。这是我做的：

连接到数据库
查询循环通过dict

这是我点击索引16时的结果：

_mysql_exceptions.OperationalError :( 2013年，＆＃39;在查询期间失去与MySQL服务器的连接＆＃39;）

它在Linux上运行，但在我的Windows环境中运行。

这是什么错误？

这是我的错误查询的代码和位置

campaignsListReportData = {}

#Connect to Database
db = MySQLdb.connect('mysqlserver', 'user', 'password', 'selecteddb')

cursor = db.cursor()
query = """
           SELECT 
               some column
           FROM 
               some table
           WHERE 
               some condition;
"""
cursor.execute(query)
data = cursor.fetchall()
for row in data:
    campaignReport = {}
    connectionState = False
    while connectionState is False:
        try:
            url = "a URL"
            r = requests.get(url, verify=False)
            feedback = r.json()
            if int(feedback['success']) is 0:
                connectionState = True
            elif int(feedback['success']) is 2:
                connectionState = True
            else:
                cursor.execute("SELECT TRIM(SUM(counter)) FROM d WHERE a = " + str(row[1]))
                counterURL = cursor.fetchone()

                counterURLNumber = 0

                if counterURL[0] == None:
                    counterURLNumber = 0
                else:
                    counterURLNumber = counterURL[0]

                urlData = []
                cursor.execute("""SELECT long_url, counter , TRIM((counter / (SELECT SUM(counter) FROM d WHERE a = """ + str(row[1]) +  """) * 100)) AS 'Percentage' """
                """FROM d """
                """WHERE c = """ + str(row[1]))
                urlQuery = cursor.fetchall()
                for row in urlQuery:
                   urlInfo = {
                        'label': row[0],
                        'value': row[1],
                        'percentage': row[2]
                   }
                   urlData.append(urlInfo)

                campaignsListReportData[str(row[0])] = campaignReport

                connectionState = True
        except requests.exceptions.RequestException as e:
            print(str(datetime.now() - timedelta(minutes=60)))
            print("Connection Failed, Trying again . . .")

db.close()

发生错误：

cursor.execute("SELECT TRIM(SUM(counter)) FROM d WHERE a = " + str(row[1]))

由于

Answer 1

尝试使用cursor.execute("SELECT TRIM(SUM(counter)) FROM d WHERE a = %s", (str(row[])))内置函数execute有2个参数，第一个是要执行的查询和第二个％s语句，因此我们可以将多个值传递给该选择。请记住，我们可以在一个语句中包含多个％s，然后在第二个参数中传递该值。阅读更多What does %s mean in Python?

Python mysql错误查询

1 个答案: