Develop Reference

"Delete from" deletes everything

I have a python function that deletes a row in mysql table using name attribute as a condition:
def delete(table: str, name: str):
cursor.execute(f"DELETE FROM {table} WHERE name = {name}")
conn.commit()
I have one row with a name attribute equal to "Name". When I use this function with "Name" it deletes every single row in a table.
I'm guessing that it has to do with passed string being same as attribute. But what would be the solution to that problem except renaming attributes?

So for one, I think you are missing quotes around name, as well as a semicolon.
For further reading you should also take a look at Python parameterized query and Prepared Statement
I do agree with the comments, that table should not be an injected argument for security reasons!
def delete(table: str, name: str):
query = f"DELETE FROM {table} WHERE name = ?"
print(query)
cursor.execute(query, (name,))
conn.commit()`
EDIT FULL WORKING EXAMPLE:
import sqlite3
conn = sqlite3.connect("test")
query_create = '''CREATE TABLE IF NOT EXISTS projects (
id integer PRIMARY KEY,
name text NOT NULL,
begin_date text,
end_date text
);'''
conn.execute(query_create)
query_insert = '''insert into projects (id, name, begin_date, end_date) values (1,"name","date","date")'''
conn.execute(query_insert)
query_select = '''select * from projects'''
cur = conn.execute(query_select)
print(cur.fetchall())
def delete(table: str, name: str):
query = f"DELETE FROM {table} WHERE name = ?"
print(query)
conn.execute(query, (name,))
delete('projects', 'name')
cur = conn.execute(query_select)
print(cur.fetchall())
Gives Output:
[(1, 'name', 'date', 'date')]
DELETE FROM projects WHERE name = ?
[]

Taking value from column in one sqlite3 table and inserting into another

I am trying to add a feature to my program where a teacher sets homework to users from a class they've made. There is a table for users where each user has a unique UserID, classname, firstname and surname. I am trying to take the userIDs of students who are in a certain class, and insert them into a HomeworkSet table. I am able to retrieve the userIDs successfully, but when I insert them into the HomeworkSet table, the values appear as (for example) ('2a1910e919a84230bfc2a7111160cade',), and I am not sure how I am meant to remove the brackets and apostraphes.
def Class_sethw():
homeworktoset = Homework_To_Set.get()
#print (homeworktoset)
conn = sqlite3.connect('MyComputerScience.db')
c = conn.cursor()
homeworkID = c.execute("SELECT HWID FROM HomeworkInfo WHERE HomeworkName = ?", (homeworktoset, )).fetchone()
print (homeworkID)
c.execute("SELECT UserID FROM users WHERE ClassName = ?", (ClassName_SetHWR, ))
homeworksetlist = c.fetchall()
print (homeworksetlist)
for i in (homeworksetlist):
#x = i
#firstname, lastname = x.split(" ")
c.execute('insert INTO HomeworkSet (HWID, StudentID)VALUES(?,?);', ((homeworkID[0]), str(i)))
conn.commit()
Label(sethw, text = "Homework Set!", fg = "GREEN").place(relx=0.205, rely=0.445, height=34, width=97)
This is the code I have used.

You should change this line:
for i in (homeworksetlist):
to:
for i in homeworksetlist:

INSERT INTO variable in python

Code:
def execute():
cursor.execute('''
INSERT INTO Testb(First_name, Last_name, Tel_number, Address)
VALUES(?,?,?,?)
''')
conn.commit()
Can we add a different type of value to the VALUES? My intent is to insert an output to the value which is outside the function. As an example, if I get the output x=456 in which x is the variable, how can I insert it to the Tele_number to the corresponding value?

You can use str.format() to allow multiple substitutions and value formatting.
For your case:
def execute():
first_name = 'Twilight'
last_name = 'Moon'
telephone = '4569876521'
address = 'Somewhere, '
cursor.execute("INSERT INTO Testb(First_name, Last_name, Tel_number, Address)
VALUES({},{},{},{})".format(first_name, last_name, telephone, address))
conn.commit()
Refer to this link to learn more about string formatting in python.

python sqlite3 query with AND

I am trying to build a simple Address book GUI that has a wx.listbox, that holds all the names in the book, first and last. Once clicked, it will return the information attached to the name from a database file. Right now I have it working by just the last name, I am trying to match first and last names. I am not, really, familiar with the SQLite 3 commands and syntax.
The function is below, this works fine now, but I want to change the query to something like:
select * from AddressBook where Last like names[0] and First like names[1]
Any help would be great!
def onListBox(self, event):
name = event.GetEventObject().GetStringSelection()
names = name.split(',')###names[0]=Last name, names[1] = first name
cursor = db.cursor()
cursor.execute("select * from AddressBook where Last like ?",('%'+names[0]+'%',) )
result = cursor.fetchall()
return result

The query from your comment should work.
Here is a small working example:
import sqlite3
conn = sqlite3.connect("test.sql")
cursor = conn.cursor()
cursor.execute("create table address_book (first_name text, last_name text)")
names = [["John", "Smith"], ["Jane", "Smith"]]
for first_name, last_name in names:
cursor.execute("insert into address_book (first_name, last_name) values (?, ?)", (first_name, last_name))
cursor.execute("select * from address_book where first_name like ? and last_name like ?", ("%" + names[0][0] + "%", "%" + names[0][1] + "%"))
print(cursor.fetchall())
It prints:
[('John', 'Smith')]

insert or replace statement not working with sqlite3 and python

Everytime I run this through the python interpreter it writes new values. for example:
name = ben
age = 10
phone = 42045042
If I run it 10 times. I get 10 duplicates in my database. I know it has to be an easy fix, but I've been working on this for hours and can't figure it out.
conn = sqlite3.connect('addressbook.db')
cur=conn.cursor()
conn.execute('''
CREATE TABLE IF NOT EXISTS people(name TEXT,
age TEXT, phone TEXT, fblink TEXT)''')
conn.execute("INSERT OR REPLACE INTO people values (?, ?, ?, ?)", ben.displayPerson())
cursor = conn.execute("SELECT name, age, phone, fblink from people")
for row in cursor:
print "NAME = ", row[0]
print "AGE = ", row[1]
print "PHONE = ", row[2]
print "FACEBOOK LINK = ", row[3], "\n"
cur.close()
conn.commit()
conn.close()

There's no primary key field.
Make a primary key field.
For example:
conn.execute('''
CREATE TABLE IF NOT EXISTS people(name TEXT primary key,
age TEXT, phone TEXT, fblink TEXT)''')
REPLACE is executed when UNIQUE constraint violation occurs. Without primary key (or unique ..), it does not happen.

Your table has no primary key, and hence SQLite doesn't know what it should "OR REPLACE" since it has nothing to base replacing on. Add a primary key.