Questions tagged [sql]
The sql tag has no usage guidance.
131 questions
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CS50 Finance - How to add to cash
I want to make it so the user can essentially add $10,000 to their current balance.
To do this, I made a user with id 26 that has $10,000. I want to add user26's funds to the current user's funds to ...
- 11
1
vote
1
answer
382
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pset7 buy - ON DUPLICATE KEY syntax question
I'm on pset7 buy, and I just need some explanation on how the ON DUPLICATE KEY syntax is supposed to look (at least I assume that's the issue). Btw, id and symbol are both unique keys in my portfolio ...
- 147
0
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1
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328
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pset7 finance app in Python - buy function won't add anything to database!
The code I've written for the parameter checks all works fine, and on clicking the buy button everything seems to work... but then nothing gets added to my database! I've combed through the SQL query ...
1
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1
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235
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pset7 why doesn't my SQL table update?
Can anyone tell me what's wrong with my INSERT INTO? The table is not updating. I get the first purchase and nothing after that.
https://gist.github.com/0bc6c50a5f399ed1a672a8a345cbc395
Here is the ...
- 105
1
vote
1
answer
509
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SQL search multiple columns with priority
I'm trying to implement the search in pset8 and want to find the most elegant and fast solution.
The way I have implemented it is to first of all check whether the search term is an int, and if so, ...
- 1,122
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166
views
How to check if an SQL table exists without relying on errors?
pset7 help pls. Trying to check if a table exists. I am getting the error "information_schema.tables does not exist". I guess information_schema is not there in our SQL version? How else could I ...
- 120
0
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1
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68
views
Flask column order randomly changes whenever I refresh local host
Whenever, I hit ctrl + s / close and re-open IDE, and then reload my local page for CS50 finance, I seem to experience a very weird issue of randomly changing column order. This happens without me ...
- 5
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1
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84
views
PSet 7: Issues with flask table output - hint needed
I am trying to produce table headings using loop in flash but I get new lines after each:
{% extends "layout.html" %}
{% block title %}
Portfolio overview
{% endblock %}
{% block main %}
{% ...
- 5
0
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1
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426
views
For register in pset 7 where I am doing wrong?
Here is my code for register user in database but it is not working, What is my mistake
@app.route("/register", methods=["GET","POST"])
def register():
if request.form["username"] == "" or request....
- 93
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2
answers
64
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PS7: Please give me a hint on flask loop usage
Despite reading documentation I cannot figure out why my loop is not functioning properly and is only dynamic for stock symbol? Am I meant to be using multiple nested loops passing all prices, holding ...
- 5
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1
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499
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Pset 7 Variable in SQL statement
I am implementing the subtraction from the user's cash and I can't figure out a way to insert variables into my sql statement. The variables are numbers here.
Here is my code:
if user_cash > ...
- 5
0
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1
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99
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pset8, import. Only even row numbers from US.txt are being written to db
I managed to import file from US.txt to places table and all seems ok, except that only rows from even numbers in file are being imported. Instead of 40975 rows I have 20487.
I tried with while loop(...
1
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1
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74
views
C$50 Finance Pset7 - Buy.php not INSERTing shares correctly
My code for Buy.php.
For some reason whenever I fill out both fields of shares and symbol correctly I get the apologize error that the data wasn't inserted into the table correctly. (I don't think I ...
- 15
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2
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114
views
PSET7 SQL Query Not Working in buy.php
This is my code for buy.php.
I think the issue is with my SQL line, which is
"INSERT INTO Stocks (user_id, symbol, shares) VALUES(?, ?, ?)
ON DUPLICATE KEY UPDATE shares = ?", $_SESSION["id"],
...
- 45
0
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1
answer
360
views
How to make search.php return results that are more relevant
For pset8 in search.php, I cannot get relevant results to show up. I am using match () against () and I really want to only use this. The problem is, for example, when I type in Cincinnati, I get ...
- 113
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1
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48
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Printing from SQL in PHP
I am trying to print text I have placed into a MySql database. I have been able to insert into the database, but I don't know what to put to take out the value/text
<?php
require("../includes/...
- 1
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1
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36
views
help me understand GROUP BY in update.php
In update.php we have this query:
"SELECT * FROM places
WHERE
(? <= latitude AND latitude <= ?)
AND
(? <= longitude AND longitude <= ?)
GROUP BY
country_code, ...
- 55
0
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1
answer
252
views
register.php pset7
I do not understand why the following code do not work as it should.
$result= query("SELECT * FROM users WHERE username = ?", $_POST["username"]);
if($result === true)
{
apologize("Username ...
- 5
0
votes
1
answer
135
views
Final Project: Trying to access phpmyadmin through CS50 ID (similar to Pset7) but find "This Webpage is Not Available"
I am trying to use SQL in more or less the exact same way as we did in pset7, but whenever I try and access phpmyadmin it tells me the web page is not available. I already checked my chmods, apache, ...
- 3
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1
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42
views
LIKE vs equal sign - basic question
I know I can use wildcards such as % with sql's LIKE. Besides this, are there any advantages of LIKE over a simple equal sign?
So, has this:
SELECT * FROM places WHERE MATCH (postal_code, place_name,...
- 55
0
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1
answer
923
views
Pset8 search.php (still) not working
I can't get sql's "match against" to work.
I thought I understood how to do this, except when I actually used sql's match (...) against (...) syntax, I got an error. This error doesn't say anything, ...
- 107
0
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1
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167
views
What does VALUES(shares) refer to in the ON DUPLICATE KEY UPDATE clause?
This is the working snippet:
query("INSERT INTO portfolio (id, symbol, shares) VALUES(?, ?, ?)
ON DUPLICATE KEY UPDATE shares = shares + VALUES(shares)",
$_SESSION['id'], $_POST["...
- 55
1
vote
2
answers
178
views
How do I use SQL transactions?
How do I use SQL transaction with the query function provided by CS50 staff?
I tried:
query("BEGIN TRANSACTION");
and even:
query("START TRANSACTION");
but these didn't work.
0
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1
answer
292
views
What is wrong with this SQL command?
query("INSERT INTO stocks (id, symbol, shares) VALUES($_SESSION["id"], $_POST["symbol"], $_POST["number"]) ON DUPLICATE KEY UPDATE shares = shares + VALUES(shares)");
I am getting this error
Parse ...
- 169
0
votes
2
answers
189
views
pset7: query problem
When I try these with query function it is giving me an error:
query("SELECT * FROM users WHERE username LIKE %?%", $_POST['username']);
query("SELECT * FROM users WHERE username LIKE '%?%'", $_POST['...
0
votes
3
answers
1k
views
Finance: Buy/Sell does not insert into MySQL history table
On pset7 and struggling with the history part.
When I buy or sell a stock, it's reflected in the portfolio and the cash available is also updated. However, it does not seem to be affecting the ...
- 131
0
votes
1
answer
75
views
SQL Order results by score, desc
What SQL query do I have to run to get all of the rows from a table, ordered from highest score to lowest score? I tried a few different queries, none worked.
Thanks,
David
- 1,211
1
vote
2
answers
98
views
How is Week 9 SQL Atomocity solved?
David said:
So in problem set seven, we give you this one line of code, which long
story short, solves this problem in MySQL.
This very long instruction that doesn't even fit onto one line on ...
- 309
0
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1
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211
views
pset7 unknown column in where clause
This throws an error saying YHOO is an unknown column...I thought 'symbol' was the column name in this query?
$id = 6;
$symbol = "YHOO";
$shares_query = query("SELECT shares FROM portfolio WHERE id = ...
2
votes
1
answer
288
views
Problem Set 7 (fighting of SQL injection attack)
Halfway the PS-text it says that using the "query'-function will also ensure "that any such placeholders' values are properly escaped so that your code is not vulnerable to SQL injection attacks.", ...
4
votes
2
answers
2k
views
How to use current timestamp or now()
In CS50 pset 7, there is a part where you have to use SQL to insert the date and time of a transaction into a table.
According to the web, there is a function to do that called CURRENT_TIMESTAMP or ...
- 85