为什么我在 SQL 语法中出现错误，无法将记录插入 MySQL 表 1064 (42000)？

Question

我想在 Python 和 Mysql 中使用 Vader 创建情绪分析。问题是，我在mysql上遇到了错误，尤其是在将数据插入数据库时​​。我得到的错误是 Failed to insert record into MySQL table 1064 (42000): You have an error in your SQL syntax;查看与您的 MariaDB 服务器版本相对应的手册，以在第 2 行的 '['compound'],'negative')' 附近使用正确的语法。代码如下：

    sql_select_Query = "select a from table1 union select b from table1"
    cursor = connection.cursor()
    cursor.execute(sql_select_Query)
    records = cursor.fetchall()


    for row in records:
        print(row)

        sid_obj = SentimentIntensityAnalyzer() 

        sentiment_dict = sid_obj.polarity_scores(row) 

        if sentiment_dict['compound'] >= 0.05 : 
            sentiment = 'positive'

        elif sentiment_dict['compound'] <= - 0.05 : 
            sentiment = 'negative'

        else : 
            sentiment = 'neutral'

        mySql_insert_query = """INSERT INTO sent (q,polarity,senti) VALUES (%s,%s,%s) """

        records_to_insert = [(row,sentiment_dict['compound'], sentiment)]

        cursor = connection.cursor()
        cursor.executemany(mySql_insert_query, records_to_insert)
        connection.commit()
        print(cursor.rowcount, "Record inserted successfully into table")

except mysql.connector.Error as error:
    print("Failed to insert record into MySQL table {}".format(error))


except Error as e:
    print("Error while connecting to MySQL", e)
finally:
    if  (connection.is_connected()):
        cursor.close()
        connection.close()

数据库表：

Answer 1

问题出在这里：

mySql_insert_query = """INSERT INTO sent (q,polarity,senti) 
    VALUES (%s,sentiment_dict['compound'],'negative') """

这表示您正在尝试将字符串 sentiment_dict['compound'] 插入数据库，而不是它所保存的值，这很可能是错误的。您可能想要这样的东西（其他查询也类似）：

mySql_insert_query = """INSERT INTO sent (q,polarity,senti) 
    VALUES (%s,%s,'negative') """

# then later

records_to_insert = [(row, sentiment_dict['compound'])]

或者更好，重构为：

if sentiment_dict['compound'] >= 0.05 : 
    sentiment = 'positive'
elif sentiment_dict['compound'] <= - 0.05 : 
    sentiment = 'negative'
else: 
    sentiment = 'neutral'

mySql_insert_query = """INSERT INTO sent (q,polarity,senti) 
    VALUES (%s,%s,%s) """

records_to_insert = [(row, sentiment_dict['compound'], sentiment)]

（顺便说一句，cursor.executemany() 似乎没有必要，因为您一次只使用一组值，尽管我怀疑您首先调试的是简单案例。）