creating a table in sqlite3 python

Question

I apologize in advance for asking such a basic question but I am new to SQlite3 and having trouble starting. I am trying to build a database with one table. I used the following code to build a table.

import sqlite3
conn = sqlite3.connect('example.db')
c = conn.cursor()
c.execute('''CREATE TABLE mytable
 (start, end, score)''')

but whenever I try to update or access the table it seems that it doesnt exist or maybe it exists in a different database. I also tried creating a table called example.mytable but I got the error: sqlite3.OperationalError: unknown database example

What am I missing? Thanks

• user1907906: Does the program this code is part of exit? When do you try to access the table?
• CL.: Works for me. Show the code that tries to update or access the table.
• user2906979: I used this method and checked and the table did exist. I closed the connection after doing conn.commit(). I then reopened it and the data was there and closed it. The third time I tried to access it I received an error that the table doesn't exist- do I have to end with committing and closing every time?
• Wang Liang: what is your solution?

Answer 1

I think that a commit is needed after inserts (schema changes such as new tables should automatically commit). I would suggest adding the full path to your database as well to make sure you are accessing the same location next time round.

Here is an extension on your code:

import sqlite3
def create():
 try:
 c.execute("""CREATE TABLE mytable
 (start, end, score)""")
 except:
 pass
def insert():
 c.execute("""INSERT INTO mytable (start, end, score)
 values(1, 99, 123)""")
def select(verbose=True):
 sql = "SELECT * FROM mytable"
 recs = c.execute(sql)
 if verbose:
 for row in recs:
 print row
db_path = r'C:\Users\Prosserc\Documents\Geocoding\test.db'
conn = sqlite3.connect(db_path)
c = conn.cursor()
create()
insert()
conn.commit() #commit needed
select()
c.close()

Output:

(1, 99, 123)

After closing the program if I log onto the SQLite database the data is still there.

Answer 2

import sqlite3;
import pandas as pd;
con=None
def getConnection():
 databaseFile="./test.db"
 global con
 if con == None:
 con=sqlite3.connect(databaseFile)
 return con
def createTable(con):
 try:
 c = con.cursor()
 c.execute("""CREATE TABLE IF NOT EXISTS Movie
 (start, end, score)""")
 except Exception as e:
 pass
def insert(con):
 c = con.cursor()
c.execute("""INSERT INTO Movie (start, end, score)
 values(1, 99, 123)""")
def queryExec():
 con=getConnection()
 createTable(con)
 insert(con)
 # r = con.execute("""SELECT * FROM Movie""")
 result=pd.read_sql_query("select * from Movie;",con)
 return result
r = queryExec()
print(r)