Prompt works in DB Browser SQLite but not in code?

Question

I’m trying to filter a list of stocks based on price data. To be honest I don’t really know what I’m doing so any help is really appreciated.
I’ll get right to the point. Basically, this prompt

        select * from (
            select symbol, name, stock_id, max(close), date
            from stock_price join stock on stock.id = stock_price.stock_id
            group by stock_id
            order by symbol
        ) where date = '2021-04-01'

works fine in DB Browser (SQLite). In the app I want it to work as a filter "New Closing High":

import sqlite3, config
from fastapi import FastAPI, Request
from fastapi.templating import Jinja2Templates
from datetime import date

app = FastAPI()
templates = Jinja2Templates(directory="templates")

@app.get("/")
def index(request: Request):
    stock_filter = request.query_params.get('filter', False)

    connection = sqlite3.connect(config.DB_FILE)
    connection.row_factory = sqlite3.Row
    cursor = connection.cursor()

    if stock_filter == 'new_closing_highs':
        cursor.execute("""
        select * from (
            select symbol, name, stock_id, max(close), date
            from stock_price join stock on stock.id = stock_price.stock_id
            group by stock_id
            order by symbol
        ) where date = ?
        """, (date.today().isoformat(),))

    else: 
        cursor.execute("""
            SELECT id, symbol, name FROM stock order by symbol
        """)

    rows = cursor.fetchall()

    return templates.TemplateResponse("index.html", {"request": request, "stocks": rows})

@app.get("/stock/{symbol}")
def index(request: Request, symbol):
    connection = sqlite3.connect(config.DB_FILE)
    connection.row_factory = sqlite3.Row
    cursor = connection.cursor()

    cursor.execute("""
        SELECT id, symbol, name FROM stock WHERE symbol = ?
    """, (symbol,))

    row = cursor.fetchall()

    cursor.execute("""
        SELECT *FROM stock_price WHERE stock_ID = ? ORDER BY date DESC
    """, (row['id'],))

    prices = cursor.fetchall()

    return templates.TemplateResponse("stock_detail.html", {"request": request, "stock": row, "bars": prices})

If the filter wasn’t defined in the code, it would just jump back to all stocks, but instead it shows an empty table and I can’t figure out why. Running this with uvicorn.

The database has two tables so far: stocks, containing all tradeable, active assets provided by Alpaca API:

id  symbol  name                                     Exchange
65  AAA     AAF First Priority CLO Bond ETF          ARCA
66  AAAU    Goldman Sachs Physical Gold ETF Shares   ARCA

and stock_price:

id stock_id    date      open    high    low     close  volume
1   65      2020-10-02  24.9127 24.925  24.9127  24.92  2944
2   65      2020-10-05  24.91   24.94   24.91    24.92  29000
3   65      2020-10-06  24.89   24.91   24.89    24.91  4019
4   65      2020-10-07  24.9017 24.91   24.9     24.91  3800
5   65      2020-10-08  24.9    24.905  24.9     24.9   1534
6   65      2020-10-09  24.88   24.91   24.88    24.89  16273

Please let me know if I haven’t provided enough info here.
thanks so much for taking the time

Asked By: thro avvay

||

Source

Answer 1

I don’t think that your query actually works.
Maybe it works coincidentally for the data you have and the specific date '2021-04-01'.
If you want to get for a specific date the highest price of each stock, you should join the tables, group by stock and aggregate:

SELECT s.symbol, s.name, s.id, MAX(p.close) max_price, p.date
FROM stock s INNER JOIN stock_price p
ON p.stock_id = s.id
WHERE p.date = ?
GROUP BY s.symbol, s.name, s.id

Answered By: forpas

Answer 2

MY BAD! I don’t have data for today yet! I thought I did, but the script didn’t run as scheduled. Should’ve just double-checked. So sorry if I wasted your time

Answered By: thro avvay

Prompt works in DB Browser SQLite but not in code?

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