SQLite exception: no such table, while successfully connecting to DB - python

When I executing the following function, I get the following response:
Failed to insert data into sqlite table: no such table: users
user_id = uuid.uuid4()
save_record.name = name
save_record.score = score
last_time = datetime.now()
try:
conn = sqlite3.connect('OnlineJeopardy.db')
cursor = conn.cursor()
print("Successfully Connected to OnlineJeopardy DB.")
sqlite_insert_query = """INSERT INTO users
(User_id, Name, Score, Last_time)
VALUES
(?, ?, ?, ?)"""
add_to_db = cursor.execute(sqlite_insert_query, (user_id, name, score, last_time))
conn.commit()
cursor.close()
except sqlite3.Error as error:
print("Failed to insert data into sqlite table: ", error)
finally:
if (conn):
conn.close()
print("The SQLite connection is closed")
When I execute this query in DB Browser, with actual values instead of placeholders, it all goes well.
I've tried swapping placeholders to actual values (as below) within the query in sqlite3 but the outcome was the same.
conn = sqlite3.connect('OnlineJeopardy.db')
cursor = conn.cursor()
print("Successfully Connected to OnlineJeopardy DB.")
sqlite_insert_query = """INSERT INTO users
(User_id, Name, Score, Last_time)
VALUES
('ID-1337', 'Adam', 20, '2020-06-12 23:18:58')"""
add_to_db = cursor.execute(sqlite_insert_query)
conn.commit()
cursor.close()

Related

how to overwrite or skip data when the same data is already existed in database?

i'm taking data from textfile which contains some duplicate data.And i'm trying to insert them into database without duplicating.i'm in trouble where inserting duplicate data.it should not be inserted again.data are not static values.
text_file = open(min_file, "r")
#doc = text_file.readlines()
for line in text_file:
field = line.split(";")
print(field)
try:
connection = mysql.connector.connect(host='localhost',
database='testing',
user='root',
password='root')
if connection.is_connected():
db_Info = connection.get_server_info()
print("Connected to MySQL Server version ", db_Info)
cursor = connection.cursor()
cursor.execute("select database();")
record = cursor.fetchone()
print("You're connected to database: ", record)
mycursor = connection.cursor()
#before inserting
mycursor.execute("Select * from ftp")
myresult = mycursor.fetchall()
for i in myresult:
print(i)
sql ="Insert into ftp(a,b,c,d) \
select * from( Select VALUES(%s,%s,%s,%s) as temp \
where not exists \
(Select a from ftp where a = %s) LIMIT 1"
mycursor.execute(sql,field)
print(mycursor.rowcount, "record inserted.")
connection.commit()
except Error as e:
print("Error while connecting to MySQL", e)
finally:
if connection.is_connected():
cursor.close()
connection.close()
print("MySQL connection is closed")
One option is to add Unique constraint and let the DB validate uniqueness, this will throw exception which you can catch and skip.

how to use one database in several python file

I working on a project and I want to use one database in two python file
but, when I run every project they created database for self
if you know please tell me how I can use that
import sqlite3
def connect():
conn = sqlite3.connect("waiters.db")
cur = conn.cursor()
cur.execute(
"CREATE TABLE IF NOT EXISTS salary (id INTEGER PRIMARY KEY , name text, age INTEGER , price INTEGER )"
)
conn.commit()
conn.close()
def insert(name, age, price):
conn = sqlite3.connect("waiters.db")
cur = conn.cursor()
cur.execute(
"INSERT INTO salary VALUES (NULL ,?,?,?)", (name ,age ,price)
)
conn.commit()
conn.close()
def view():
conn = sqlite3.connect("waiters.db")
cur = conn.cursor()
cur.execute(
"SELECT * FROM salary"
)
rows = cur.fetchall()
conn.close()
return rows
def search(name="", age="", price=""):
conn = sqlite3.connect("waiters.db")
cur = conn.cursor()
cur.execute(
"SELECT * FROM salary WHERE name = ? OR age = ? OR price = ?", (name, age, price)
)
rows = cur.fetchall()
conn.close()
return rows
def delete(id):
conn = sqlite3.connect("waiters.db")
cur = conn.cursor()
cur.execute("DELETE FROM salary WHERE id=?", (id,))
conn.commit()
conn.close()
def update(id, name, age, price):
conn = sqlite3.connect("waiters.db")
cur = conn.cursor()
cur.execute(
"UPDATE salary SET name = ?, age = ?, price = ? WHERE id = ?", (name, age, price, id)
)
conn.commit()
conn.close()
def update_pay_money(name, price):
conn = sqlite3.connect("waiters.db")
cur = conn.cursor()
cur.execute(
"UPDATE salary SET price = ? WHERE name = ?", (price, name)
)
conn.commit()
conn.close()
connect()
enter image description here
Giving exact path like /path/to/waiters.db while connecting to your database should solve your problem?
This line should be changed while connecting to database.
conn = sqlite3.connect("/path/to/waiters.db")
as Other mentioned for using a sqllite3 db in multiple files you can use their absolute or relative path, for example if you have 'DBs' & 'section-1' & 'section-2' directories and your python file are in section directories you can access the database file in each section by using somthing like this '"../DBs/waiters.db"' and so on for others... but whatf of you try make multiple tables in a database file in tgat way you don need to have multiple databases and its the standard way,
hope it's help

psycopg2: update multiple rows with one query

I tried to update multiple rows (approx. 350000) with a single query by implementing the following function:
def update_items(rows_to_update):
sql_query = """UPDATE contact as t SET
name = e.name
FROM (VALUES %s) AS e(id, name)
WHERE e.id = t.id;"""
conn = get_db_connection()
cur = conn.cursor()
psycopg2.extras.execute_values (
cur, sql_query, rows_to_update, template=None, page_size=100
)
While trying to run the function above, only 31 records were updated. Then, I tried to update row by row with the following function:
def update_items_row_by_row(rows_to_update):
sql_query = """UPDATE contact SET name = %s WHERE id = %s"""
conn = get_db_connection()
with tqdm(total=len(rows_to_update)) as pbar:
for id, name in rows_to_update:
cur = conn.cursor()
# execute the UPDATE statement
cur.execute(sql_query, (name, id))
# get the number of updated rows
# Commit the changes to the database
conn.commit()
cur.close()
pbar.update(1)
The latter has updated all the records so far but is very slow (estimated to end in 9 hours).
Does anyone know what is the efficient way to update multiple records?
By splitting the list into chunks of size equal to page_size, it worked well:
def update_items(rows_to_update):
sql_query = """UPDATE contact as t SET
name = data.name
FROM (VALUES %s) AS data (id, name)
WHERE t.id = data.id"""
conn = get_db_connection()
cur = conn.cursor()
n = 100
with tqdm(total=len(rows_to_update)) as pbar:
for i in range(0, len(rows_to_update), n):
psycopg2.extras.execute_values (
cur, sql_query, rows_to_update[i:i + n], template=None, page_size=n
)
conn.commit()
pbar.update(cur.rowcount)
cur.close()
conn.close()
The problem with your original function appears to be that you forgot to apply commit. When you execute an insert/update query with psycopg2 a transaction is opened but not finalized until commit is called. See my edits in your function (towards the bottom).
def update_items(rows_to_update):
sql_query = """UPDATE contact as t SET
name = e.name
FROM (VALUES %s) AS e(id, name)
WHERE e.id = t.id;"""
conn = get_db_connection()
cur = conn.cursor()
psycopg2.extras.execute_values(cur, sql_query, rows_to_update)
## solution below ##
conn.commit() # <- We MUST commit to reflect the inserted data
cur.close()
conn.close()
return "success :)"
If you don't want to call conn.commit() each time you create a new cursor, you can use autocommit such as
conn = get_db_connection()
conn.set_session(autocommit=True)

unique values for a duration in mysql

I am new in mysql, I have a table with two cols tag_id and time_stamp, I use a python connector. I need to insert new tag_id just only if did not insert the same tag_id in last 5 min (or some other duration). How can I do that using python mysql.connector?
create table:
import mysql.connector
from mysql.connector import Error
try:
connection = mysql.connector.connect(host='localhost',
database='test',
user='root',
password='root')
mySql_Create_Table_Query = """CREATE TABLE tags (
Id int(11) NOT NULL AUTO_INCREMENT,
tag_id varchar(250) NOT NULL,
time_stamp Datetime NOT NULL,
PRIMARY KEY (Id)) """
cursor = connection.cursor()
result = cursor.execute(mySql_Create_Table_Query)
print("Laptop Table created successfully ")
except mysql.connector.Error as error:
print("Failed to create table in MySQL: {}".format(error))
finally:
if (connection.is_connected()):
cursor.close()
connection.close()
print("MySQL connection is closed")
Insertion function:
def insertVariblesIntoTable(tag, time_stamp):
try:
connection = mysql.connector.connect(host='localhost',
database='test',
user='root',
password='root')
cursor = connection.cursor()
mySql_insert_query = """INSERT INTO tags(tag_id, time_stamp )
VALUES (%s, %s) """
recordTuple = (tag, time_stamp)
cursor.execute(mySql_insert_query, recordTuple)
connection.commit()
print("Record inserted successfully into tags table")
except mysql.connector.Error as error:
print("Failed to insert into MySQL table {}".format(error))
finally:
if (connection.is_connected()):
cursor.close()
connection.close()
print("MySQL connection is closed")
I'd just do a query of the table like this:
import arrow
check = '''select max(timestamp) from tags where tag_id = {}'''
try:
with conn.cursor() as curs:
curs.execute(check.format(tag_id))
max_time = curs.fetchone()
if max_time <= arrow.utcnow().shift(minutes=-5).format('YYYY-MM-DD HH:mm:ss'):
#run the inserts
else:
pass

Basic Database made with SQLITE3

I created a basic database in python with sqlite3 which takes in 3 values and stores them. Now where the problem lies is that when I created a function that is supposed to output the values, no syntax errors were displayed on terminal and none of my values were printed. Im guessing this is a minor error but I am not able to spot it.
The code is given below:
import sqlite3
def create_table():
conn = sqlite3.connect("lite.db")
cur = conn.cursor()
cur.execute("CREATE TABLE IF NOT EXISTS store (item TEXT, quantity
INTEGER, price FLOAT)")
conn.commit()
conn.close()
def insert(item, quantity, price):
conn = sqlite3.connect("lite.db")
cur = conn.cursor()
cur.execute("INSERT INTO store VALUES ('?, ?, ?')", (item, quantity,
price))
conn.commit()
conn.close()
insert("Mug", 8, 6)
def view():
conn = sqlite3.connect("lite.db")
cur = conn.cursor()
cur.execute("SELECT * FROM store")
rows = cur.fetchall()
conn.close()
return rows
print(view())
Again no error messages were displayed but my values are not displayed.
I have tried it. it seems the single quotes are not needed in the insert. See modified below:
import sqlite3
def create_table():
conn = sqlite3.connect("lite.db")
cur = conn.cursor()
cur.execute("CREATE TABLE IF NOT EXISTS store (item TEXT, quantity INTEGER, price FLOAT)")
conn.commit()
conn.close()
def insert(item, quantity, price):
conn = sqlite3.connect("lite.db")
cur = conn.cursor()
cur.execute("INSERT INTO store VALUES (?,?,?)", (item, quantity, price))
conn.commit()
conn.close()
def view():
conn = sqlite3.connect("lite.db")
cur = conn.cursor()
cur.execute("SELECT * FROM store")
rows = cur.fetchall()
conn.close()
return rows
create_table()
insert("Mug", 1, 5)
print(view())

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