Python：使用 mysqldb 将 MySQL 表作为字典导入？

Question

任何人都知道我如何使用 mysqldb 将包含大量行的 MySQL 表转换为 Python 中的字典对象列表？

我的意思是将一组 MySQL 行（包含列“a”、“b”和“c”）转换为如下所示的 Python 对象：

data = [ { 'a':'A', 'b':(2, 4), 'c':3.0 }, { 'a':'Q', 'b':(1, 4), 'c':5.0 }, { 'a':'T', 'b':(2, 8), 'c':6.1 } ]

谢谢:)

Answer 1

MySQLdb 为此有一个单独的游标类，即 DictCursor。您可以将要使用的游标类传递给 MySQLdb.connect()：

import MySQLdb.cursors
MySQLdb.connect(host='...', cursorclass=MySQLdb.cursors.DictCursor)

Answer 2

如果您需要使用更多游标，并且只需要一个是 MySQLdb.cursors.DictCursor，您可以这样做：

import MySQLdb
db = MySQLdb.connect(host='...', db='...', user='...t', passwd='...')

list_cursor = db.cursor()
dict_cursor = db.cursor(MySQLdb.cursors.DictCursor)

Answer 3

我认为mysql.connector 比 MySQLdb 更容易将 select 转换为 dict，并且支持更多 Python 版本：

cursor = conn.cursor(dictionary=True)

---

详细示例：

import mysql.connector # pip install mysql-connector-python

mydb = mysql.connector.connect(host="localhost", user="user", passwd="pass", database="dbname")
cursor = conn.cursor(dictionary=True)
sql = "SELECT * FROM `table` WHERE 1"
mycursor.execute(sql)
rows = mycursor.fetchall()
for row in rows:
    row["col"]

Answer 4

这是一篇古老的帖子，虽然这个答案并不完全是 OP 所要寻找的，但它的思路大致相同。它不是生成字典列表，而是生成列表字典：

还想我会提供生成字典的完整代码：

import MySQLdb
import MySQLdb.cursors

dict_serv = MySQLdb.connect(host = 'localhost', user = 'root', passwd = 'mypassword', cursorclass = MySQLdb.cursors.DictCursor)

with dict_serv as c:
    c.execute("USE mydb")
    c.execute("SELECT col1, col2 FROM mytable WHERE id = 'X123'")

    # Save the dictionary to a separate variable
    init_dict = c.fetchall()

    # This line builds the column headers
    sql_cols = [ col[0] for col in c.description ]

    # This is a list comprehension within a dictionary comprehension
    # which builds the full dictionary in a single line.  
    sql_dict = { k : [ d[k] for d in init_dict ] for k in sql_cols }

产量：

{ 'col1': ['apple','banana'], 'col2':['red','yellow'] }

Answer 5

使用 Python >= 3.6;在这里它可以这样做：

OBS.：这里我使用 2 个数据库类型 ORACLE 12g 和 MYSQL 5.6 ；并且主服务器是ORACLE，mysql只有部分软件使用……然后……我的连接类的代码：

这里是来自 shellscript 代码...然后我只是带一个字符串在这里显示...

myp3 = 'XXXXXXXXXXXXXXXXXXXXXXXXXXX PASSWD MYSQL XXXXXXXXXXXXXXXXXXXXXXXXXXX'

import cx_Oracle
import MySQLdb
import MySQLdb.cursors

class oracle(object):
    def __init__(self, serverORACLE=3, MYSQL='N', serverMYSQL=3):
        ## ORACLE connection!
        try:

        if serverORACLE == 1:
            self.db = cx_Oracle.connect('sys/[xxxxPASSWORDxxxxx]@[xxxxxIP/HOSTxxxxxx]:1521/DATABASE_X')
            print('ORACLE [ system/[xxxxPASSWORDxxxxx]@[xxxxxIP/HOSTxxxxxx]:1521 ] ===> CONNECTED')

        if serverORACLE == 2:
            self.db = cx_Oracle.connect('system/[xxxxPASSWORDxxxxx]@[xxxxxIP/HOSTxxxxxx]:1521/DATABASE_X')
            print('ORACLE [ system/[xxxxPASSWORDxxxxx]@[xxxxxIP/HOSTxxxxxx]:1521 ] ===> CONNECTED')

        if serverORACLE == 3:
            self.db = cx_Oracle.connect('userLEVEL1/[xxxxPASSWORDxxxxx]@[xxxxxIP/HOSTxxxxxx]:1521/DATABASE_X')
            print('ORACLE [ userLEVEL1/[xxxxPASSWORDxxxxx]@[xxxxxIP/HOSTxxxxxx]:1521 ] ===> CONNECTED')

        if serverORACLE == 4:
            self.db = cx_Oracle.connect('userLEVEL2/[xxxxPASSWORDxxxxx]@[xxxxxIP/HOSTxxxxxx]:1521/DATABASE_X')
            print('ORACLE [ userLEVEL2/[xxxxPASSWORDxxxxx]@[xxxxxIP/HOSTxxxxxx]:1521 ] ===> CONNECTED')
            
        self.cursor = self.db.cursor()
        
    except Exception as e:
        count = 0
        S1 = ''
        for W in str(e):
            S1+=W
            count+=1 
            if count >= 40:
                S1+=' \n'
                count = 0
        print('\n\n ORACLE DATABASE ===> CONECTION FAILED!', 
                    '\n error - module: ', S1)

    ##conexao MYSQL
    if MYSQL=='S': 
        try:
            if serverMYSQL == 1:
                self.dbMySQL = MySQLdb.connect(user='root', host='XXXXXX HOST XXXXX', use_unicode=True, cursorclass=MySQLdb.cursors.DictCursor,
                                                charset='utf8', port=3306, passwd=myp3, db='XXXX')
                print('MySQL [ root / XXXXXX HOST XXXXX:3306 ] ===> CONNECTED')

            if serverMYSQL == 2:
                self.dbMySQL = MySQLdb.connect(user='XXXX USER XXXXX', host='XXXXXX HOST XXXXX', use_unicode=True, cursorclass=MySQLdb.cursors.DictCursor,
                                                charset='utf8', port=3306, passwd=myp3, db='XXXX')
                print('MySQL [ XXXX USER XXXXX / XXXXXX HOST XXXXX:3306 ] ===> CONNECTED')

            self.cursorMYSQL = self.dbMySQL.cursor()
        
        except Exception as e:
            count = 0
            S1 = ''
            for W in str(e):
                S1+=W
                count+=1 
                if count >= 40:
                    S1+=' \n'
                    count = 0
            print('\n\n MYSQL DATABASE ===> CONECTION FAILED!', 
                    '\n error - module: ', S1)

"""