搜索sqlite3数据库时的Python错误

Question

#!/usr/bin/python
import sqlite3

conn = sqlite3.connect("/home/michael/Dropbox/lagniappe/database.db")

cursor = conn.cursor()

query = raw_input('Search for a title:')

cursor.execute("SELECT * FROM nerd WHERE title LIKE '%?%';", query)

print cursor.fetchall()

返回错误:

michael@piplup:~$ python sqlite.py 
Search for a title:test
Traceback (most recent call last):
  File "sqlite.py", line 10, in <module>
    cursor.execute("SELECT * FROM nerd WHERE title LIKE '%?%';", query)
sqlite3.ProgrammingError: Incorrect number of bindings supplied. The current statement uses 0, and there are 4 supplied.

我想让它做的就是将从数据库接收到的数据打印到控制台。最终我想操纵这些数据，但我只需要查询正常工作。

Answer 1

这里有两个问题。首先，参数应该是一个序列——Python 将其解释为一个包含四个字符的列表，而不是一个包含四个字符的字符串。

其次，占位符必须是整个元素，而不是引号。您需要自己添加百分比字符:

query = raw_input('Search for a title:')
query = '%' + query + '%'
cursor.execute("SELECT * FROM nerd WHERE title LIKE ?", (query,))