Insert 2 date values into columns in sqlite db using python - python-3.x

New to using sqlite with python. I am trying to insert two date values into two date columns in sqlite db via Python.
import sqlite3
def create_connection(db_file):
# Create a database connection to a SQLite database
# Param: db_file as str. Return: connection objects or None
try:
conn = sqlite3.connect(db_file)
cur = conn.cursor()
return conn, cur
except Error as e:
print (e)
return None
my_conn, my_cur = create_connection(dpd_sqlite_db_dir)
def create_sqlite_table_if_nonexist(conn, table_name):
sql = 'create table if not exists '+table_name+' (data_download_date datetime, script_executed_date datetime)'
conn.execute(sql)
create_sqlite_table_if_nonexist(my_conn, 'df_timestamp_en')
def insert_timestamp(conn, timestamp):
# execute insert into db
sql = ''' INSERT INTO df_timestamp_en (data_download_date, script_executed_date) VALUES(?,?) '''
cur = conn.cursor()
cur.execute(sql, timestamp)
return cur
timestamp_info = ('2018-10-30', '2018-11-30')
insert_timestamp(my_conn, timestamp_info)
It runs and created the table with two date columns, but it doesn't insert the timestamp_info's values.

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counting strings through columns

I'm pretty new to python or programming at all so I'd like to get help on the following problem
My table is set up like this:
https://i.imgur.com/KFPq2DI.png
Now I try to count all '✓' and set the number to column Teilnahme.
teilnahmencounter(ctx):
i=0
# Connect
connection = sqlite3.connect("kekse.db")
# cursor
cursor = connection.cursor()
# Abfrage
sql = "SELECT * FROM kekse ORDER BY ID"
cursor.execute(sql)
connection.commit()
for dsatz in cursor:
i = 0
for x in range(2 , 19):
if str(dsatz[x]) == '✓':
i += 1
cursor.execute('UPDATE kekse SET Teilnahme='+str(i)+' WHERE ID=?', dsatz[0]
)
connection.commit()
#print(dsatz[1], i, "Teilnahmen")
connection.close()

Try and use cast in your update where its getting updated -
import sqlite3
# Connect
con = sqlite3.connect("dbname.db")
# cursor
cur = con.cursor()
for row in cur.execute("select * from testtab"):
print(row)
cur.execute("update testtab set id=21 where id = cast("+str(2)+" as int)")
con.commit()
con.close()

table as var in cur.execute

I'm noob at python, and I'm trying to do some operations in some tables.
At the moment I'm doing this with hard coding the tables:
cur.execute("select id,email from table1;")
but I'm want to change the tables to and variable to construct a function, like:
cur.execute("select id,email from table;")
How I can do this?
Many thanks
I'm using python3 with psycopg2
#open connection with db
conn = psycopg2.connect(host="localhost",database="test", user="test", password="test")
cur = conn.cursor()
#Select id
cur.execute("select id,email from customers;")
#put ids on list
row = cur.fetchone()
Also I tried this:
sql = "select id,email from %s"
val = customers
cur.execute(sql, val)
And I have this error:
File "updateemails.py", line 14, in <module>
val = (customers)
NameError: name 'customers' is not defined```

update sqlite columns based on other columns information

I am trying to use information from a sqlite db and update another columns with some conditions using Python 3.6
python 3.6 and sqlite
def open_days(signed_date,completed_date):
fmt = '%Y-%m-%d'
if completed_date == '':
if signed_date:
sdate = datetime.strptime(signed_date, fmt)
tdate = datetime.now()
delta = str((tdate - sdate).days)
return delta
else:
sdate = datetime.strptime(signed_date, fmt)
cdate = datetime.strptime(completed_date, fmt)
delta = str((cdate - sdate).days)
return delta
conn = sqlite3.connect('mydb.db')
cur = conn.cursor()
cur.execute("SELECT * FROM data_table")
for row in cur:
cur.execute("UPDATE data_table SET days_open=? WHERE numid=?", (open_days(row[1],row[2]),row[0]))
cur.fetchall()
cur.close()
conn.commit()
I am expecting the result to be:
numid,signed_date,completed_date, number_of_days
1234,2019-05-15,,16
2345,2019-04-29,,32
3456,2019-04-29,2019-05-13,14
4567,,,None
the value are not udpated with the correct value if the number of days is set manually
numid,signed_date,completed_date, number_of_days
1234,2019-05-15,,16
2345,2019-04-29,,16
3456,2019-04-29,2019-05-13,16
4567,,,16
Note that it can be that no signed date and no completed date is already register into the db as per example showing some blank space between coma.
if signed date and completed date are registered then the number of day is the difference between completed date and signed date
if only signed date is registered then number of day is the difference between today's date and signed date
if no signed date then number of day is None

I have found a way to update the rows:
conn = sqlite3.connect('mydb.db')
conn.create_function('open_days', 2 , open_days)
cur = conn.cursor()
for row in cur.execute('SELECT signed_date, completed_date, open_days(signed_date,completed_date) FROM data_table'):
cur.execute('UPDATE data_table SET days_open=(open_days(signed_date,completed_date))')
cur.close()
conn.commit()
change to as per Sam input:
conn = sqlite3.connect('mydb.db')
conn.create_function('open_days', 2 , open_days)
cur = conn.cursor()
cur.execute('UPDATE data_table SET days_open=(open_days(signed_date,completed_date))')
cur.close()
conn.commit()

adding key:value from dictionary to sqlite3 db and retrieving them back

I am saving sequences with different ids associated with them as two column in sqlite3 DB where sequence is a column and ids_string are another column. I have problem with retrieving from the database
The dictionary is created as uniqe_sequence = [list of ids]
the sequence is a string of roughly 7000 characters or less and the list of ids could be up to 1 million characters
import sys
from Bio import SeqIO
from Bio.Seq import Seq
import time
import sqlite3
conn = sqlite3.connect('Sausql_012419.db')
c = conn.cursor()
c.execute("create table Sau (sequence text, list_of_ids text)")
for record in sequences_dict_d:
c.execute("insert into Sau values (?,?)", (record,'._/'.join(sequences_dict_d[record])))
conn.commit()
c.execute("SELECT COUNT(*) FROM Saureus_panproteome")
sql_count = c.fetchall()
print("saved sql database of {} proteins in --- {:.3f} seconds ---".format(sql_count[0][0],time.time() - start_time))
c.close()
conn.close()
#retrieval exact sequence match
for record in SeqIO.parse(queryfile, _format):
conn = sqlite3.connect('Sausql_012419.db')
c = conn.cursor()
c.execute('select list_of_ids from Sau where sequence = str(record.seq)')
print(c.fetchall()) # or do something with the list_of_ids

how to translate datebase tables(sqlite3) to numpy array

a datebase contained 80 tables ,every table is a 18000x4 matrix ,how can I translate these to a 80x18000x4 numpy array?
the db : https://drive.google.com/open?id=0B3bNSNFik5wGdm1DYnJwNHBJMVU
I wrote a function. Do you have any better idea?
import sqlite3 as sql
import os
def db_to_array(db,r,c):
db = sql.connect(db)
cursor = db.cursor()
cursor.execute("SELECT name FROM sqlite_master WHERE type='table';")
tables = cursor.fetchall()
wd=os.getcwd()
if not os.path .exists(wd +'/temp/'):
os.makedirs(wd +'/temp/')
for table_name in tables:
table_name = table_name[0]
table = pd.read_sql_query("SELECT * from %s" % table_name, db)
table.to_csv(wd +'/temp/'+ table_name + '.csv', index_label='index')
ss=os.listdir(wd +'/temp/')
print(len(ss))
dd=np.empty([len(ss),r,c])
for i in range(len(ss)):
ddd=np.array(pd.read_csv(wd +'/temp/'+ss[i]))
print(i)
print(ddd.shape)
dd[i,:,:]=ddd[:,0:r]
return dd

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