Develop Reference

Retrieving text from sqlite without string formatting for comparison

Saving a string into a sqlite table, retrieving it again and comparing it to the original requires some filters to work and i dont know why exactly.
tl;dr
How can i retrieve string Data from the SQLITE DB without requiring Filter Nr 3 as its dangerous for more complex strings ?
import sqlite3
RAWSTRING = 'This is a DB Teststing'
# create database and table
currentdb = sqlite3.connect('test.db')
currentdb.execute('''CREATE TABLE tickertable (teststring text)''')
# enter RAWSTRING into databasse
currentdb.execute('''INSERT INTO tickertable VALUES(?);''', (RAWSTRING,))
# get RAWSTRING from database
cursorObj = currentdb.cursor()
cursorObj.execute('SELECT * FROM tickertable')
DB_RAWSTRING = cursorObj.fetchall()
currentdb.commit()
currentdb.close()
# Prints This is a DB Teststing
print('originalstring : ', RAWSTRING)
# Prints [('This is a DB Teststing',)]
print('retrieved from DB: ', DB_RAWSTRING)
# Get first entry from List because fetchall gives a list
FILTER1_DB_RAWSTRING = DB_RAWSTRING[0]
# Convert the Listelement to String because its still a listelement and comparing fails to string
FILTER2_DB_RAWSTRING = str(FILTER1_DB_RAWSTRING)
# Remove annoying db extra characters and i dont know why they exist anyway
FILTER3_DB_RAWSTRING = FILTER2_DB_RAWSTRING.replace("'", "").replace("(", "").replace(")", "").replace(",", "")
if RAWSTRING == FILTER3_DB_RAWSTRING:
print('Strings are the same as they should')
else:
print('String are not the same because of db weirdness')

So here's your problem: fetchall returns a list of tuples. This means that casting them to a string puts pesky parenthesis around each row and commas between each element of each row. If you'd like to retrieve the raw information from each column, that can be done by indexing the tuples:
entries = cursorObj.fetchall()
first_row = entries[0]
first_item = first_row[0]
print(first_item)
This ought to print just the content of the first row and column in the DB. If not, let me know!
David

Pass values from python list to Cassandra query

Beginner here.
I have the following circumstances.
A text file with each line containing a name.
A cassandra 3.5 database
A python script
The intention is to have the script read from the file one line (one name) at a time, and query Cassandra with that name.
FYI, everything works fine except for when I try to pass the value of the list to the query.
I current have something like:
#... driver import, datetime imports done above
#...
with open(fname) as f:
content = f.readlines()
# Loop for each line from the number of lines in the name list file
# num_of_lines is already set
for x in range(num_of_lines):
tagname = str(content[x])
rows = session.execute("""SELECT * FROM tablename where name = %s and date = %s order by time desc limit 1""", (tagname, startDay))
for row in rows:
print row.name + ", " + str(row.date)
Everything works fine if I remove the tagname list component and edit the query itself with a name value.
What am I doing wrong here?

Simply building on the answer from #Vinny above, format simply replaces literal value. You need to put quotes around it.
for x in content:
rows = session.execute("SELECT * FROM tablename where name ='{}' and date ='{}' order by time desc limit 1".format(x, startDay))
for row in rows:
print row.name + ", " + str(row.date)

You can simply iterate over content:
for x in content:
rows = session.execute("SELECT * FROM tablename where name = {} and date = {} order by time desc limit 1".format(x, startDay))
for row in rows:
print row.name + ", " + str(row.date)
....
Also, you don't need to have 3 quotes for the string. Single quotes is good enough (3 quotes is used for documentation / multiple line comments in python)
Note that this might end in a different error; but you will be iterating on the lines instead of iterating over an index and reading lines.

Using a 'one key to many values' entry in SQLite3 database with Python

I have a text file that contains many different entries. What I'd like to do is take the first column, use each unique value as a key, and then store the second column as values. I actually have this working, sort of, but I'm looking for a better way to do this. Here is my example file:
account_check:"login/auth/broken"
adobe_air_installed:kb_base+"/"+app_name+"/Path"
adobe_air_installed:kb_base+"/"+app_name+"/Version"
adobe_audition_installed:'SMB/Adobe_Audition/'+version+'/Path'
adobe_audition_installed:'SMB/Adobe_Audition/'+version+'/ExePath'
Here is the code I'm using to parse my text file:
val_dict = {}
for row in creader:
try:
value = val_dict[row[0]]
value += row[1] + ", "
except KeyError:
value = row[1] + ", "
val_dict[row[0]] = value
for row in val_dict.items():
values = row[1][:-1],row[0]
cursor.execute("UPDATE 'plugins' SET 'sets_kb_item'= ? WHERE filename= ?", values)
And here is the code I use to query + format the data currently:
def kb_item(query):
db = get_db()
cur = db.execute("select * from plugins where sets_kb_item like ?", (query,))
plugins = cur.fetchall()
for item in plugins:
for i in item['sets_kb_item'].split(','):
print i.strip()
Here is the output:
kb_base+"/Installed"
kb_base+"/Path"
kb_base+"/Version"
It took me many tries but I finally got the output the way I wanted it, however I'm looking for critique. Is there a better way to do this? Could my entire for item in plugins.... print i.strip() be done in one line and saved as a variable? I am very new to working with databases, and my python skills could also use refreshing.
NOTE I'm using csvreader in this code because I originally had a .csv file - however I found it was just as easy to use the .txt file I was provided.

read and display data from text file from database query in Python

I am newbie in python and i am stuck with kind of database engine problem in python
I have text file database table(person.text) with a delimiter(|) separated in python. For example
sue|45|Happy Lane|456-3245
John|43|67 Drury Lane|897-3456
Mark|21|Stuffy Street|345-7896
Now i want a functionality that take queries from user and fetch data from this text file and display. queries can be select,update (with or without where clause).
For example If user give input as "select name from person " then output would be
sue
John
Mark
I am confuse which data structure should i use ??

Instead of data = f.split("|") it should be data = line.split("|").
I need to write query in user input and then it must be interpreted by code. If i use above solution then how can a match my SQL queries with dictionary ?
Thanks

If you want to maintain your current text based database you would probably need to parse it manually then store it do a local dictionary (defaultdict makes it easy) to allow for keyword searching. I added a numeric primary key to help store the data in a keyword-searchable form
from collections import defaultdict
person = defaultdict(lambda: dict())
with open("path/to/person.txt", "r") as f:
primary_key = 0
for line in f:
data = line.split("|")
person[primary_key]["name"] = data[0]
person[primary_key]["age"] = data[1]
person[primary_key]["address"] = data[2]
person[primary_key]["pnum"] = data[3]
primary_key += 1
Then you would have a local dictionary named person that can be searched through using keywords inputted by the end user.
Searching:
query = "select name from person"
query_items = query.split(" ")
if query_items[0] == "select":
table = eval(query_items[3])
for value in table.values():
print(value[query_items[1]])

How to Convert from String to Tuple in python?

When I am retrieving a record from DB getting the record as below
('("2014-02-21 07:10:40",ManualNo,184,vsp,AP10123456,aaaaa,Coconut-Na,5,10)',)
and I need to get the data as tuple like:
("2014-02-21 07:10:40",ManualNo,184,vsp,AP10123456,aaaaa,Coconut-Na,5,10)
without using split function and then want to get the individual values from it.
like
record[0] = 2014-02-21 07:10:40
record[1] = ManualNo
and so on...

You can simply split the string over the comma:
data = ('("2014-02-21 07:10:40",ManualNo,184,vsp,AP10123456,aaaaa,Coconut-Na,5,10)',)
record = data[0].lstrip('(').rstrip(')').split(',')