如何使用 SQLite3 和 Python 在 SQLite table 中更新行

Question

我是 python 的新手，我不太了解 sql 的东西。目前是团队树屋的第 6 周，所以如果这些是新手问题，请在这里与我交流。

目标

导入包含 stock_tickers 和其他 5 列数据的 CSV
将 CSV 转换为 pandas 数据帧
将数据框导入数据库。如果已经存在unique stock_ticker 则不添加新行，而是检查其他5列中的数据是否不同。如果是则更新它。

现在我可以完成第 1 步和第 2 步以及第 3 步的一半。在此处的帮助下，能够使循环工作正常进行。如果 csv 中有一个新的 stock_ticker 行，它将把它添加到数据库中。如果现有 stock_ticker 的数据发生变化，它不会进行任何更新。

for i in range(len(df)):
    try:
        df[df.index == i].to_sql(name='stocks', con=conn, if_exists='append', index=False)
        conn.commit()
    except sqlite3.IntegrityError:
        pass

当前代码如下所示

import pandas as pd
from pandas import DataFrame
from pandas import ExcelWriter
import csv
import sqlite3

### IMPORT CSV ###
stock_csv_file = pd.read_csv (r'C:\Users\home\Desktop\code_projects\FIRE_Dashboard\db\alpha_vantage_active_stocks.csv')

### CHANGING INDEX NAMES FROM CSV TO TABLE NAMES ###
df = pd.DataFrame(stock_csv_file)
df = df.rename(columns = {"symbol":"stock_ticker", "name":"stock_name", "exchange":"stock_exchange", "ipoDate":"stock_ipoDate", "delistingDate":"stock_delistingDate", "status":"stock_status"})

### UPDATING DATABSE WITH SQLITE3###
conn = sqlite3.connect('stockmarket.db')
c = conn.cursor()

insert_statement = """
INSERT INTO stocks (stock_ticker,
                    stock_name,
                    stock_exchange,
                    stock_ipoDate,
                    stock_delistingDate,
                    stock_status
                    )
VALUES (?, ?, ?, ?, ?, ?)
ON CONFLICT (stock_ticker) DO UPDATE
    SET (stock_status)"""
    

for i in range(len(df)):
    values = tuple(df.iloc[i])
    c.execute(insert_statement, values)

我遇到的错误

Traceback (most recent call last):
  File "update_stock_tickers.py", line 71, in <module>
    c.execute(insert_statement, values)
sqlite3.OperationalError: incomplete input

找到这些谈论它的帖子，但仍然迷路 >.<

How to use variables in SQL statement in Python?
Loop through individual rows and update those rows SQLite3 Python

非常感谢任何帮助。

求解后的代码

import pandas as pd
from pandas import DataFrame
from pandas import ExcelWriter
import csv
import sqlite3

### IMPORT CSV ###
stock_csv_file = pd.read_csv (r'C:\Users\home\Desktop\code_projects\FIRE_Dashboard\db\alpha_vantage_active_stocks.csv')

### CHANGING INDEX NAMES FROM CSV TO TABLE NAMES ###
df = pd.DataFrame(stock_csv_file)
df = df.rename(columns = {"symbol":"stock_ticker", "name":"stock_name", "exchange":"stock_exchange", "ipoDate":"stock_ipoDate", "delistingDate":"stock_delistingDate", "status":"stock_status"})

### UPDATING DATABSE WITH SQLITE3###
conn = sqlite3.connect('stockmarket.db')
c = conn.cursor()

insert_statement = """
INSERT INTO stocks (stock_ticker,
                    stock_name,
                    stock_exchange,
                    stock_ipoDate,
                    stock_delistingDate,
                    stock_status
                    )
VALUES (?, ?, ?, ?, ?, ?)
ON CONFLICT (stock_ticker) DO UPDATE
    SET stock_status = EXCLUDED.stock_status"""
    

for i in range(len(df)):
    values = tuple(df.iloc[i])
    c.execute(insert_statement, values)
    conn.commit()

Answer 1

这是您查询的 ON CONFLICT 子句：

ON CONFLICT (stock_ticker) DO UPDATE
    SET (stock_status)

这不是有效的 SQLite 语法。如果你想更新 stock_status 而另一行已经存在相同的 stock_ticker，你可以使用 pseudo-table EXCLUDED 像这样：

INSERT INTO stocks (stock_ticker,
                    stock_name,
                    stock_exchange,
                    stock_ipoDate,
                    stock_delistingDate,
                    stock_status
                    )
VALUES (?, ?, ?, ?, ?, ?)
ON CONFLICT (stock_ticker) DO UPDATE
    SET stock_status = EXCLUDED.status

如何使用 SQLite3 和 Python 在 SQLite table 中更新行

How to do update rows in SQLite table using SQLite3 and Python

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