multidimensional array to database in python - python

I am trying to figure out a way to put a two dimensional array (using python) into an sqlite database. My array:
['hello', 'hello', 'hello'], ['hello', 'hello', 'hello']
What I want is for each tuple of 'hello's would a new row with each 'hello' being its own attribute. I'm not sure what I'm trying to do is even possible (I hope it is). I tried following a few other posts but I keep getting the error:
sqlite3.InterfaceError: Error binding parameter 0 - probably unsupported type.
Does anyone know how to insert a multidimensional array into a sqlite database? Any help would be appreciated. Here is my code:
import sqlite3
array2d = [['hello' for x in xrange(3)] for x in xrange(3)]
var_string = ', '.join('?' * len(array2d))
conn = sqlite3.connect('sample.db')
c = conn.cursor()
c.execute('''CREATE TABLE sample (Name TEXT, Line_1 TEXT, Line_2 TEXT)''')
query_string = 'INSERT INTO sample VALUES (%s);' % var_string
c.execute(query_string, array2d)

Use the cursor.executemany() method to insert a sequence of rows in one go:
query_string = 'INSERT INTO sample VALUES (?, ?, ?)'
c.executemany(query_string, array2d)
conn.commit()
Don't forget to conn.commit() the transaction.
I've not bothered with formatting the SQL parameters here, for demonstration purposes; you don't really want to do so here anyway, as your number of columns is fixed at well (from the CREATE TABLE definition).

Related

How to insert a list containing values seperated by comma into MySQL database using python

I have to insert a list having integer values into a column of MySQL database table using Python. First I tried
cur.execute("insert into time_Interval (name, time_interval_list) values (%s, %s)",\
# (user_name, interval_list))
Where "interval_list" is the list variable having values that I want to insert into "time_interval_list" column of "time_Interval" table. Code is working but does not insert the values. Then I tried this solution changing the code as
var_string = ','.join('?' * len(interval_list))
cur.execute("insert into time_Interval (name, time_interval_list) values (%s, %s)",\
(user_name, var_string))
Again, code was working fine but inserts a list of question mark. I am unable to find the solution.
How to do this correctly. Any suggestion will be appreciated
Try changing
var_string = ','.join('?' * len(interval_list))
to
var_string = ','.join(interval_list)
The following code helped me bulk insert data into a database table using Python.
You can first create a tuple of tuples from the data you want to insert as follows
var_string = ','.join(cur.mogrify("(%s,%s)", x).decode('utf-8') for x in interval_list)
The interval_list would include both name and time_interval_list values whehn creating the tuple of tuples. Then run exceute command giving the tuple of tuples as input to the values.
cur.execute("INSERT INTO time_Interval (name, time_interval_list) VALUES " + var_string)
This command bulk inserts data into a database table very quickly.

Update SQLITE DB with multiple python lists

I'm attempting to update my sqlite db with 2 python lists. I have a sqlite db with three fields. Name, number, date. I also have three python lists with similar names. I'm trying to figure out a way to update my sqlite db with data from these 2 lists. I can get the db created, and even get a single column filled, but I cant seem to update it correctly or at all. Is there a way to INSERT both lists at once? Rather than INSERT a single column and then UPDATE the db with the other?
Here is what I have so far:
name_list = []
number_list = []
date = now.date()
strDate = date.strftime("%B %Y")
tableName = strDate
sqlTable = 'CREATE TABLE IF NOT EXISTS ' + tableName + '(name text, number integer, date text)'
c.execute(sqlTable)
conn.commit()
for i in name_list:
c.execute('INSERT INTO January2018(names) VALUES (?)', [i])
conn.commit()
I can't seem to get past this point. I still need to add another list of data (number_list) and attach the date to each row.
Here's what I have on that:
for i in number_list:
c.execute('UPDATE myTable SET number = ? WHERE name', [i])
conn.commit()
Any help would be much appreciated. And if you need more information, please let me know.
You can use executemany with zip:
c.executemany('INSERT INTO January2018 (name, number) VALUES (?, ?)', zip(name_list, number_list))
conn.commit()

How to add multiple Columns into Sqlite3 from a for loop in Python

Admittedly I a still very new to both Python and Sqlite3, and I am attempting to add the contents of two lists into a database so that one list is in the first column and the second list shows up in the second column. To this point, I have been unsuccessful. I am defenitely making a fundamental error, and the error message that I get is this: "sqlite3.InterfaceError: Error binding parameter 0 - probably unsupported type."
my code is this:
import sqlite3
names = ['Tom', 'Dick', 'Harry']
ids = ['A452', 'B698', 'Kd9f']
conn = sqlite3.connect('testforinput.db')
c = conn.cursor()
c.execute("CREATE TABLE thetable(name TEXT, id TEXT)")
index = 0
for link in names:
idofperson = ids[index]
c.execute("INSERT INTO thetable(name, id)VALUES(?, ?)", ( [link], idofperson ))
index+=1
conn.commit()
conn.close()
The error occurs because of the for loop specifically the "idofperson" variable
The desired outcome is that I would like to have two columns created in sql one being name and the other being id.
Any help would be greatly appreciated.
I think you just change
index =0
for link in names:
idofperson = ids[index]
c.execute("INSERT INTO thetable(name, id)VALUES(?, ?)", ( [link], idofperson ))
to this (use enumrate and change [list] to list, because you pass a list into a column need TEXT type):
for index, link in enumrable(names):
idofperson = ids[index]
c.execute("INSERT INTO thetable(name, id)VALUES(?, ?)", ( link, idofperson ))
your variable index is not increasing.try using the enumerate on for loop. or just add index += 1 after execute
the error is occurring because of the unsupported data type you are trying to push in, you can't store list as it is, you need to change to another supported data types, i like this solution ....it worked for me https://stackoverflow.com/a/18622264/6180263
for your problem, try this:
import sqlite3
names = ['Tom', 'Dick', 'Harry']
ids = ['A452', 'B698', 'Kd9f']
data = zip(names, ids)
conn = sqlite3.connect('testforinput.db')
c = conn.cursor()
c.execute("CREATE TABLE thetable(name TEXT, id TEXT)")
for d in data:
sql = "INSERT INTO thetable (name, id) VALUES ('%s', '%s'); " % d
c.execute(sql)
conn.commit()
conn.close()
I suggest change data to a list of dict, like this [{'name':'Tom', 'id': 'A452'}, {'name':'dick', 'id':'B698'}..]
and you can generate insert sql by data, this make the insert more flexible.

use only variables to model an sqlite table with python

I'm practicing in SQLite and Python. I'm trying to build a TABLE using only user prompts as database objects. After some extensive searches (official documentation says nothing about this kind of syntax-please correct me!) I found this method:
new_table = raw_input('Enter a table name: ')
column = raw_input('Enter column name: ')
cur.execute(''' CREATE TABLE IF NOT EXISTS {tn} ({col})'''\
.format(tn = new_table, col = column))
It works very nice and I find it intuitive. My problem is with INSERT INTO syntax. While the following code works ok:
cur.execute("INSERT INTO {tn} ({col}) VALUES (?)", ('goodmorning')\
.format(tn=new_table, col=column))
This code below, won't work:
insdata = raw_input('Insert data for column: ')
cur.execute("INSERT INTO {tn} ({col}) VALUES (?)", (insdata,)\
.format(tn=new_table, col=column))
and fails with error: 'tuple' object has no attribute format.
Question is: what is the proper syntax to assign insdata value to SQLite VALUES?
If you write this is a slightly clearer fashion, you'll see what's going on:
cur.execute(
"INSERT INTO {tn} ({col}) VALUES (?)",
(insdata,).format(tn=new_table, col=column)
)
You're not formatting the string, you're formatting the a tuple of arguments. Instead, you want:
cur.execute(
"INSERT INTO {tn} ({col}) VALUES (?)".format(tn=new_table, col=column),
(insdata,)
)
or perhaps a little more clearly :
sql = "INSERT INTO {tn} ({col}) VALUES (?)".format(tn=new_table, col=column)
cur.execute(sql, (insdata,))
In this case your line continuation character is not needed at all (since you're inside a function call) but if it were needed it would make much more sense to position it between arguments rather than between an object and the method invocation on the object.
I think you are invoking format method of tuple (which appears not to have one) instead of a string with SQL query:
cur.execute("INSERT INTO {tn} ({col}) VALUES ({val})".format(tn=new_table,col=column,val='goodmorning'))

Populating sqlite3 database in Python loop

I have constructed a database but when I loop through my data to populate it, I get the following error:
OperationalError: no such column: tmp1
Code:
with con:
cur = con.cursor()
cur.execute("CREATE TABLE TESTTABLE(X REAL, Y REAL)")
for i in xrange(0,5):
tmp1 = array[i,0]
tmp2 = array[i,1]
with con:
cur.execute("""INSERT INTO TESTTABLE VALUES(tmp1,tmp2)""")
Basically I have a big array that I want to transfer into a database. This probably isn't the most efficient way of going about it. Suggestions?
If you want to insert values into a row, you need to pass those values along as SQL parameters to the .execute() call:
with con:
for i in xrange(0,5):
tmp1 = array[i, 0]
tmp2 = array[i, 1]
cur.execute("""INSERT INTO TESTTABLE VALUES(?, ?)""", (tmp1, tmp2))
The ? characters are parameters, and they are filled, in order, by values takes from the second argument to .execute(), a tuple. The above code will insert the numbers 0 through to 4 as pairs into the database.
Names in the SQL code have no correlation to names you define in Python, values can only be passed in explicitly.

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