python - Python 中 Sqlite 查询提供的绑定(bind)数量不正确

Question

在 python 中运行以下代码时，出现错误:提供的绑定(bind)数量不正确。当前语句使用 0，并且提供了 1。对于查询语句。

conn = sqlite3.connect('viber_messages2')

cur = conn.cursor()
cur = cur.execute("""SELECT DISTINCT messages.conversation_id
                FROM messages
                INNER JOIN participants  ON messages.participant_id = participants._id
                WHERE messages.conversation_id IS NOT NULL;""")

query = ("""SELECT messages._id, messages.body, messages.conversation_id, messages.participant_id, participants_info.number, participants_info.contact_name
        FROM messages
        INNER JOIN
        participants ON messages.participant_id = participants._id
        INNER JOIN
        participants_info ON participants.participant_info_id = participants_info._id;""")

with open('messages.html', 'w') as h, open('test.txt', 'w') as t:
for convo in cur.fetchall():
    df = pd.read_sql_query(query, conn, params=convo)

    # HTML WRITE
    h.write(df.to_html())
    h.write('<br/>')

    # TXT WRITE
    t.write(df.to_string())
    t.write('\n\n')

cur.close()
conn.close()

Answer 1

让我们仔细看看您的查询

SELECT messages._id, messages.body, messages.conversation_id, messages.participant_id, participants_info.number, participants_info.contact_name
        FROM messages
        INNER JOIN
        participants ON messages.participant_id = participants._id
        INNER JOIN
        participants_info ON participants.participant_info_id = participants_info._id

这里没有可以绑定(bind)参数的占位符。但是你如何执行这个查询呢？

df = pd.read_sql_query(query, conn, params=convo)

你应该这样做

df = pd.read_sql_query(query, conn)