使用Python将RESTAPI中的JSON数据插入PostgreSQL表

我试图将json api的每个元素插入到我的postgres表中

但我得到了以下错误：

Traceback (most recent call last):
  File "c:/Users/myname/Documents/repos/docker-playground/parse_json_to_postgres.py", line 20, in <module>
    cursor.execute(f"INSERT into catfacts(data) VALUES (  {cat_fact}  )")
psycopg2.errors.SyntaxError: syntax error at or near "{"
LINE 1: INSERT into catfacts(data) VALUES (  {'status': {'verified':...
                                             ^

将数据插入表的MyPython代码：

CREATE TABLE cat_facts (
    id serial NOT NULL PRIMARY KEY,
    data jsonb NOT NULL
);

import requests, json, psycopg2  


cat_facts_json = requests.get('https://cat-fact.herokuapp.com/facts').json


conn = psycopg2.connect(user="postgres",
                                password="password",
                                host="localhost",
                                port="5432",
                                database="postgres")

cursor = conn.cursor()

for cat_fact in cat_facts_json():
    cursor.execute(f"INSERT into catfacts(data) VALUES ( \' {cat_fact} \' )")

INSERT INTO cat_facts(data) VALUES ('{"status":{"verified":true,"sentCount":1},"type":"cat","deleted":false,"_id":"58e008800aac31001185ed07","user":"58e007480aac31001185ecef","text":"Wikipedia has a recording of a cat meowing, because why not?","__v":0,"source":"user","updatedAt":"2020-08-23T20:20:01.611Z","createdAt":"2018-03-06T21:20:03.505Z","used":false}');
INSERT INTO cat_facts(data) VALUES ('{"status":{"verified":true,"sentCount":1},"type":"cat","deleted":false,"_id":"58e008630aac31001185ed01","user":"58e007480aac31001185ecef","text":"When cats grimace, they are usually \"taste-scenting.\" They have an extra organ that, with some breathing control, allows the cats to taste-sense the air.","__v":0,"source":"user","updatedAt":"2020-08-23T20:20:01.611Z","createdAt":"2018-02-07T21:20:02.903Z","used":false},{"status":{"verified":true,"sentCount":1},"type":"cat","deleted":false,"_id":"58e00a090aac31001185ed16","user":"58e007480aac31001185ecef","text":"Cats make more than 100 different sounds whereas dogs make around 10.","__v":0,"source":"user","updatedAt":"2020-08-23T20:20:01.611Z","createdAt":"2018-02-11T21:20:03.745Z","used":false}');

....

API=

我正在努力实现的目标：

CREATE TABLE cat_facts (
    id serial NOT NULL PRIMARY KEY,
    data jsonb NOT NULL
);

import requests, json, psycopg2  


cat_facts_json = requests.get('https://cat-fact.herokuapp.com/facts').json


conn = psycopg2.connect(user="postgres",
                                password="password",
                                host="localhost",
                                port="5432",
                                database="postgres")

cursor = conn.cursor()

for cat_fact in cat_facts_json():
    cursor.execute(f"INSERT into catfacts(data) VALUES ( \' {cat_fact} \' )")

INSERT INTO cat_facts(data) VALUES ('{"status":{"verified":true,"sentCount":1},"type":"cat","deleted":false,"_id":"58e008800aac31001185ed07","user":"58e007480aac31001185ecef","text":"Wikipedia has a recording of a cat meowing, because why not?","__v":0,"source":"user","updatedAt":"2020-08-23T20:20:01.611Z","createdAt":"2018-03-06T21:20:03.505Z","used":false}');
INSERT INTO cat_facts(data) VALUES ('{"status":{"verified":true,"sentCount":1},"type":"cat","deleted":false,"_id":"58e008630aac31001185ed01","user":"58e007480aac31001185ecef","text":"When cats grimace, they are usually \"taste-scenting.\" They have an extra organ that, with some breathing control, allows the cats to taste-sense the air.","__v":0,"source":"user","updatedAt":"2020-08-23T20:20:01.611Z","createdAt":"2018-02-07T21:20:02.903Z","used":false},{"status":{"verified":true,"sentCount":1},"type":"cat","deleted":false,"_id":"58e00a090aac31001185ed16","user":"58e007480aac31001185ecef","text":"Cats make more than 100 different sounds whereas dogs make around 10.","__v":0,"source":"user","updatedAt":"2020-08-23T20:20:01.611Z","createdAt":"2018-02-11T21:20:03.745Z","used":false}');

....

请参见此处

比如：

from psycopg2.extras import Json

cursor.execute("INSERT into catfacts(data) VALUES (%s)", [Json(cat_fact)])

我现在开始工作了：

for cat_fact in cat_facts_json:

    data = json.dumps(cat_fact)
    insert_query = "insert into cat_facts (data) values (%s) returning data"
    cursor.execute(insert_query, (data,))
    conn.commit()
    conn.close()

我考虑了你对Stefano Frazzetto和Adrian Klaver的评论

• json.dumps有效
• 我没有直接在执行查询中执行参数

我仍然认为，这是一种非常奇怪的语法，数据后加逗号：

cursor.execute(insert_query, (data,))

---

你看过这里的答案了吗？除了@StefanoFrazzetto post外，请参见此部分，了解不应使用格式化字符串的原因。@Adriankeraver我喜欢文档部分，其中说：“永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，永远，我在cat_facts_json（）中的cat_facts中尝试了这个方法：cursor.execute（“插入到catfacts（数据）值（%s）”%json.dumps（cat_facts）），但仍然没有出现相同的错误。对于cat_facts_json（）中的cat_facts，这个方法是：sql=“插入catfacts（数据）值（%s）”游标。执行（sql，cat_事实）retuns:Traceback（最近一次调用）：游标中第33行的文件“c:/Users/user/Documents/repos/docker Playerly/parse_json_to_postgres.py”。执行（sql，cat_事实）TypeError:dict不是一个序列还不完全存在，但更接近。打印工作，它返回每个cat事实对象。插入不知何故不工作。对于cat_事实中的cat_事实，json:print（cat_事实）cursor.execute（“insert into cat_事实（数据）值（%s）”、[json（cat_事实）]和missed（），在我的get查询中，现在是requests.get（“而不是requests.get”（）。谢谢Adrian，请将此添加到您的问题中，以便正确格式化。当您这样做时，还包括

print（cat\u fact）

的结果。还要定义“not working”。我的回答假设

cat\u fact

是一个Python对象，就像您从

json.loads（json\u str）中得到的一样

。这是一个漫长的过程：

insert\u query=“insert into cat\u facts（data）value（%s）returning data”游标。execute（insert\u query，（Json（cat\u fact））

（data，）

是一个元组，Python语法要求它有一个逗号，以区别于括号中的值，因此：

t=（1，）t[0]1，t=（1）t[0]“int”对象不可下标

。如果不想这样做，请使用列表。