使用python在postgresql数据库中插入json数据问题

Question

主文件

data = []
with open('data.json') as f:
    for line in f:
        data.append(json.loads(line))
f.close()

fields = [
    'id', #integer
    'name', #varchar
    'log_date', #date
    'log_time', #timestamp
    'login', #timestamp
    'logout' #timestamp
]

for item in data:
    my_data = [item[field] for field in fields]
    insert_query = "INSERT INTO employee VALUES (%d, %s, %s, %s, %s, %s)"
    cur.execute(insert_query, tuple(my_data))

数据.json

[
    {
        "id": 1,
        "name": "Prosenjit Das",
        "log_date": "2019-03-02",
        "log_time": "12:10:12.247257",
        "login": null,
        "logout": null
    },
    {
        "id": 2,
        "name": "Sudipto Rahman",
        "log_date": "2019-03-02",
        "log_time": "12:10:12.247257",
        "login": "11:26:45",
        "logout": "10:49:53"
    },
    {
        "id": 3,
        "name": "Trump Khatun",
        "log_date": "2019-03-02",
        "log_time": "12:10:12.247257",
        "login": null,
        "logout": null
    }
]

postgresql 列字段

我的数据库连接没问题。 在图片第 37 行中，当我使用转储而不是加载时，第 50 行显示了另一个问题，即“类型错误：字符串索引必须是整数”。 注意这里的 json 格式类型是一个列表。 这种问题但不完全是我见过很多但正确不起作用。

谢谢。

Answer 1

所以我会在这里做一些改变

with open('data.json') as f:
    data = json.load(f)

# no need to do f.close() since we are using a context manager

fields = [
    'id', #integer
    'name', #varchar
    'log_date', #date
    'log_time', #timestamp
    'login', #timestamp
    'logout' #timestamp
]

for item in data:
    my_data = [item[field] for field in fields]
    insert_query = "INSERT INTO employee (id, name, log_date, log_time, login, logout) VALUES (%s, %s, %s, %s, %s, %s)"

    # also ALL placeholders must be %s even if it is an integer
    cur.execute(insert_query, tuple(my_data))

此外，如果您使用psycopg2模块进行数据库操作，您可以执行以下操作

from psycopg2.extras import execute_values

my_data = [tuple(item[field] for field in fields) for item in data]
insert_query = "INSERT INTO employee (id, name, log_date, log_time, login, logout) VALUES %s"
execute_values(cursor, insert_query, my_data) 

Answer 2

将 json 加载到 dicts 列表中一次 + 删除一个额外的逗号

import json

with open('data.json', 'r') as f:
    data = json.load(f)
# now  you can iterate and push to entries to DB

数据.json

[
    {
        "id": 1,
        "name": "Prosenjit Das",
        "log_date": "2019-03-02",
        "log_time": "12:10:12.247257",
        "login": null,
        "logout": null
    },
    {
        "id": 2,
        "name": "Sudipto Rahman",
        "log_date": "2019-03-02",
        "log_time": "12:10:12.247257",
        "login": "11:26:45",
        "logout": "10:49:53"
    },
    {
        "id": 3,
        "name": "Trump Khatun",
        "log_date": "2019-03-02",
        "log_time": "12:10:12.247257",
        "login": null,
        "logout": null
    }, --> was removed
]