Python：从mysql表中选择时，元组索引必须是整数，而不是str

I have following method that I select all the ids from table and append them to a list and return that list. But when execute this code I end up getting tuple indicies must be integers... error. I have attached the error and the print out along with my method:

我有以下方法，我从表中选择所有ID并将它们附加到列表并返回该列表。但是当执行这段代码时我最终得到元组指标必须是整数...错误。我已经附加了错误和打印输出以及我的方法：

def questionIds(con):
    print 'getting all the question ids'
    cur = con.cursor()
    qIds = []
    getQuestionId = "SELECT question_id from questions_new"
    try:
        cur.execute(getQuestionId)
        for row in cur.fetchall():
            print 'printing row'
            print row
            qIds.append(str(row['question_id']))
    except Exception, e:
        traceback.print_exc()
    return qIds

Printing what my method does:

打印我的方法：

Database version : 5.5.10 
getting all the question ids
printing row
(u'20090225230048AAnhStI',)
Traceback (most recent call last):
  File "YahooAnswerScraper.py", line 76, in questionIds
    qIds.append(str(row['question_id'][0]))
TypeError: tuple indices must be integers, not str

7 个解决方案

#1

The python standard mysql library returns tuples from cursor.execute. To get at the question_id field you'd use row[0], not row['question_id']. The fields come out in the same order that they appear in the select statement.

python标准的mysql库从cursor.execute返回元组。要获取question_id字段，您需要使用row [0]，而不是row ['question_id']。这些字段的出现顺序与它们在select语句中出现的顺序相同。

A decent way to extract multiple fields is something like

提取多个字段的一种不错的方法就像

for row in cursor.execute("select question_id, foo, bar from questions"):
    question_id, foo, bar = row

#2

There are multiple cursor types in the MySQLdb module. The default cursor returns the data in a tuple of tuples. When we use a dictionary cursor, the data is sent in a form of Python dictionaries. This way we can refer to the data by their column names. Source

MySQLdb模块中有多种游标类型。默认游标返回元组元组中的数据。当我们使用字典光标时，数据以Python字典的形式发送。这样我们就可以通过列名来引用数据。资源

#!/usr/bin/python
# -*- coding: utf-8 -*-

import MySQLdb as mdb

con = mdb.connect('localhost', 'testuser', 'test623', 'testdb')

with con:

    cur = con.cursor(mdb.cursors.DictCursor)
    cur.execute("SELECT * FROM Writers LIMIT 4")

    rows = cur.fetchall()

    for row in rows:
        print row["Id"], row["Name"]

#3

I know the question is old, but I found another way to do it that I think it is better than the accepted solution. So I'll just leave it here in case anyone needs it.

我知道问题已经过时了，但我发现了另一种方法，我认为这比接受的解决方案更好。所以我会把它放在这里，万一有人需要它。

When creating the cursor you can use

创建光标时，您可以使用

cur = connection.cursor(dictionary=True);

which will allow you to do exactly what you want without any additional modifications.

这将允许您完全按照自己的意愿进行操作，无需任何其他修改。

rows = cur.fetchall()
for row in rows:
    print "%s %s %s" % (row["Id"], row["Name"], row["Price"])

#4

you can see here: enter link description here ,I think its your want

你可以在这里看到：在这里输入链接描述，我想你想要的

#!/usr/bin/python
# -*- coding: utf-8 -*-

import sqlite3 as lite


con = lite.connect('test.db')    

with con:

    con.row_factory = lite.Row # its key

    cur = con.cursor() 
    cur.execute("SELECT * FROM Cars")

    rows = cur.fetchall()

    for row in rows:
        print "%s %s %s" % (row["Id"], row["Name"], row["Price"])

#5

To retrieve data from database use dictionary cursor

从数据库中检索数据使用字典光标

import psycopg2
import psycopg2.extras
con = psycopg2.connect(database="test", user="test", password="test", host="localhost", port="5432")
if con != None:
    print "Connection Established..!\n"
else:
    print "Database Connection Failed..!\n"

cur = con.cursor(cursor_factory=psycopg2.extras.DictCursor)

cur.execute("SELECT * FROM emp")
rows = cur.fetchall()
for row in rows:
    print "%s %s %s" % (row["id"],row["name"],row["address"])

print "\nRecords Display Successfully"
con.commit()
con.close()

#6

Integer indices are not allowed. To get it working you can declare the DICT as specified below:

不允许使用整数索引。为了使其正常工作，您可以按照以下规定声明DICT：

VarName = {}

Hope this works for you.

希望这对你有用。

#7

-1

row is a tuple. When you do row['question_id'], you are trying to access a tuple using a string index which gives you an error.

行是一个元组。当您执行row ['question_id']时，您尝试使用字符串索引访问元组，这会给您一个错误。

#1