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Database queries with SELECT xxx FROM database WHERE Relay = "value from a string"

I'm wondering about if it's possible to get data from a database with this query: SELECT Name FROM fraleon WHERE Relay = "value from a string"?
When I try to put in a string in the query it comes with a message that the column doesn't exists.
I have just started with programming, so hope my question isn't to stupid ;-) I'm trying to make an app where i have a QtableWidget and a QScrollbar where the value from the scrollbar (1 - 100) is used to change to the next relay.
con = sqlite3.connect("C:\Leonclient\LocalDB\LeonDBlite.db")cur = con.cursor()
value = 5
for row in cur.execute('SELECT Name FROM fraleon where Relay = value'):
print(row)
Traceback (most recent call last):
File "C:\Users\xxx\AppData\Local\Temp/ipykernel_10292/3072186007.py", line 1, in <module>
for row in cur.execute('SELECT Name FROM fraleon where Relay = (Value)'):
OperationalError: no such column: Value

You may need to concatenate the query string with variable value otherwise it will be considered literally 'value'
for row in cur.execute('SELECT Name FROM fraleon where Relay = ' + str(value)):

You can try to write the query -
SELECT Name FROM fraleon WHERE Relay like '%somevalue%'
That way you will specify a sub-string of the Relay's column values

Is there a way to pass a Python variable into an SQL Query? [duplicate]

This question already has answers here:
How do I get around not being able to parse a table name into a python sqlite query?
(3 answers)
Closed 3 years ago.
I am trying to pass the result of a user input into an SQL query, like so:
def select_rows(conn):
table_choice = input("Choose a table: ")
cur = conn.cursor()
cur.execute("SELECT * FROM %s", table_choice)
rows = cur.fetchall()
for row in rows:
print(row)
but I get this Error:
Database Path: C:\Users\Morgan\Desktop\SQL\chinook.db
Choose a table: album
Traceback (most recent call last):
File "C:\Users\Morgan\Desktop\SQL\SQL.py", line 27, in <module>
select_rows(conn)
File "C:\Users\Morgan\Desktop\SQL\SQL.py", line 20, in select_rows
cur.execute("SELECT * FROM %s", table_choice)
sqlite3.OperationalError: near "%": syntax error
Any suggestions?

You can use f-string as well:
cur.execute(f"SELECT * FROM {table_choice}")
But be careful with user's input and query. You should write a function to validate the input.

you need to format the query before executing it...:
cur.execute("SELECT * FROM {}".format(table_choice))

cur.execute("SELECT * FROM ?", (table_choice,))

Populate sqlite3 database from csv: Syntax error around '?'

Following a previous post concerning the population of a sqlite3 database from a csv file in python, I have used the code exactly as written but keep coming up with: Traceback (most recent call last):
File "Z:/KS4/Computer Science/OCR corsework/Task 1 Database/populate.py", line 10, in <module>
cursor.execute(query, data)
sqlite3.OperationalError: near "?": syntax error
This is the code:
import csv, sqlite3
connection = sqlite3.connect("TutorGroup.db")
with open ('studentsEmail-master.csv', 'r') as f:
r = csv.reader(f)
data = next(r)
query = 'insert into dbo.students ({0})'
query = query.format(','.join('?' * len(data)))
cursor = connection.cursor()
cursor.execute(query, data)
for data in reader:
cursor.execute(query, data)
cursor.commit()

https://www.sqlite.org/lang_insert.html
You need the word values in the query:
query = 'insert into dbo.students values ({0})'
# ^^^^^^

sqlite3.OperationalError: no such column. But that's not a column

I seem to be getting a rather odd error. And, for the life of me I can't figure out what's wrong. But on a piece of SQLite code, I'm getting this error:
Traceback (most recent call last):
File "test.py", line 38, in <module>
populateTables()
File "test.py", line 20, in populateTables
curs.execute("SELECT * FROM tracks WHERE ISRC = " + line[8])
sqlite3.OperationalError: no such column: USTCZ0993316
The odd part is that USTCZ0993316 is a piece of data that I want to compare to. I don't know why it seems to think it is a column. Here is a much small version that gives the same issue.
import sqlite3
import csv
def tableSetup(name):
if(name=="tracks"):
curs.execute("CREATE TABLE tracks(id INT UNIQUE, name TINYTEXT, album_id INT, client_id INT, acr_record_num INT, ISRC TINYTEXT UNIQUE, track_length TINYTEXT, client_share FLOAT)")
def populateTables():
tracks_csv=csv.reader(open('tables/tracks.csv', 'rU'), delimiter=";", quotechar='"')
tracks_csv.next()
for line in tracks_csv:
curs.execute("SELECT * FROM tracks WHERE id = " + line[0])
if not curs.fetchall():
if "\"" in line[1]:
line[1]=line[1].replace("\"","'")
curs.execute("INSERT INTO tracks VALUES("+line[0]+",\""+line[1]+"\","+line[2]+","+line[3]+","+line[4]+",\""+line[5]+"\",\""+line[7]+"\","+line[12]+")")
override_csv=csv.reader(open('tables/artist_override.csv', 'rU'), delimiter=",", quotechar='"')
override_csv.next()
for line in override_csv:
curs.execute("SELECT * FROM tracks WHERE ISRC = " + line[8])
print curs.fetchone()
#Set required Table Names
tables = ["tracks"]
testOut=open('tables/testOut.txt','w')
conn = sqlite3.connect('tables/test.db')
curs = conn.cursor()
# Create table if they don't already exist
curs.execute("SELECT name FROM sqlite_master WHERE type='table'")
tableResults = curs.fetchall()
print
for table in tables:
if not any(table == result[0] for result in tableResults):
tableSetup(table)
populateTables()
conn.commit()
curs.close()

If it doesn't have quotes then it's a column or a number.
curs.execute("SELECT * FROM tracks WHERE ISRC = ?", (line[8],))
[Edit: "%s" isn't proper syntax. It should be "?". Also, if you're going to be condescending, at least be right about it.]

Why doesn't this work (sqlite, python)

I tried to do this in the interpreter and I can get it to work but inside my function it doesn't
What I'm trying to do:
cursor = dbconnect.cursor()
cursor.execute("""SELECT * FROM credits WHERE phone = ?""",(phone,))
data = cursor.fetchone()
firstname = data[1] #the db is set as firstname in position 1 after the id(primekey)
I'm actually extracting all the data using this method just with different variables
The Error I get when I do it inside the function:
firstname = data[1]
TypeError: 'NoneType' object is not subscriptable
As a note: I put a print statement after the data object to see what it was returning, in the interpreter it returns the tuple i'm searching for, inside the function it's returning
'None'
FULL CODE:
def FindByPhone(self,phone):
'''Find Credit by phone number ONLY'''
dbconnect = sqlite3.connect(self.dbname)
cursor = dbconnect.cursor()
cursor.execute("""SELECT * FROM credits WHERE phone = ?""",(phone,))
data = cursor.fetchone()
first = data[1]
last = data[2]
phone = data[3]
credit = data[4]
cid = data[0]
self.SetVariables(first,last,phone,credit,cid)
cursor.close()
dbconnect.close()
return

I think the problem is that your function doesn't check if there was a matching row in the database. you will get this error if no row is being returned:
#!/usr/bin/python
try:
import sqlite3
except:
from pysqlite2 import dbapi2 as sqlite3
#prepare testcase
db="/tmp/soverflow.sqlite"
dbconnect = sqlite3.connect(db)
c = dbconnect.cursor()
c.execute("""create table credits
(id int not null primary key, firstname varchar(50), phone varchar(30),amount int not null)""")
c.execute("""INSERT INTO credits (id,firstname,phone,amount) VALUES (1,'guybrush','123-456',24)""")
c.execute("""INSERT INTO credits (id,firstname, phone,amount) VALUES (2,'elaine','1337-1337',18)""")
dbconnect.commit()
c.close()
def print_firstname(phone):
cursor = dbconnect.cursor()
cursor.execute("""SELECT * FROM credits WHERE phone = ?""",(phone,))
data = cursor.fetchone()
firstname = data[1]
cursor.close() # cleanup
print firstname
print "testing existing row"
print_firstname('1337-1337')
print "testing missing row"
print_firstname('nothere')
=>
./soverflow_sqlite.py
testing existing row
elaine
testing missing row
Traceback (most recent call last):
File "./soverflow_sqlite.py", line 31, in <module>
print_firstname('not-in-db')
File "./soverflow_sqlite.py", line 23, in print_firstname
firstname = data[1]
TypeError: 'NoneType' object is not subscriptable
Solution:
Add a check if there was a row returned from your query