I got this code:
cursor.execute('SELECT nom FROM productes WHERE listacompra = 1')
producteslc = cursor.fetchone()
The problem is that when I do print producteslc, it returns (u'Natillas',), when the value on the SQL Database is just Natillas.
What could I do to have a variable with value = Natillas? I'm trying to do some stuff with split but I'm not able to do it at my own.
Thank you
The result of fetchone is a tuple of the values of one row.
Since you only fetch a single column, the result is a tuple singleton: (u'Natillas',)
To get the string:
producteslc = cursor.fetchone()[0]
See: Tuples and Sequences in the doc
EDIT
To fetch several rows, you can use fetchall() function:
rows = cursor.fetchall()
for row in rows:
print(row[0])
To print each name.
Related
I'm using the below Python script to loop around a SQL Server table and save the values to a list.
However, I don't want the brackets \ commas etc. When I run the below the records in the list look like this:
('TN12345', )
I just want the below - how it exists in the SQL table:
TN12345
This is my script:
import pyodbc
connstr = 'DRIVER={SQL Server};SERVER=XXXXXXXXXXX;DATABASE=XXXXXXXXXXX;Trusted_Connection=yes;'
conn = pyodbc.connect(connstr)
cursor = conn.cursor()
cursor.execute("""SELECT TN_Number FROM Table""")
records = cursor.fetchall()
insertObject = []
columnNames = [column[0] for column in cursor.description]
for record in records:
insertObject.append( dict( zip( columnNames , record ) ) )
for i in range(len(records)):
print(records[i])
This
('TN12345', )
is tuple with one element, representing row in database, if you can guarantee that your query will always return exactly 1 column then you might use [0] to access single element in said tuple, in your case replace
for i in range(len(records)):
print(records[i])
using
for i in range(len(records)):
print(records[i][0])
alternatively you might use for loop directly (without caring about index) in following way
for record in records:
print(record[0])
If you want to get all elements one by one in your tuples:
for i in range(len(records)):
for j in records[i]:
print(j)
Advantage is it will return every entry in your tuples no matter the length of the tuple or the length of the list of tuples.
I am using sqlite3 in python 3 I want to get only the updated data from the database. what I mean by that can be explained as follows: the database already has 2 rows of data and I add 2 more rows of data. How can I read only the updated rows instead of total rows
Note: indexing may not help here because the no of rows updating will change.
def read_all():
cur = con.cursor()
cur.execute("SELECT * FROM CVT")
rows = cur.fetchall()
# print(rows[-1])
assert cur.rowcount == len(rows)
lastrowids = range(cur.lastrowid - cur.rowcount + 1, cur.lastrowid + 1)
print(lastrowids)
If you insert rows "one by one" like that
cursor.execute('INSERT INTO foo (xxxx) VALUES (xxxx)')
You then can retrieve the last inserted rows id :
last_inserted_id = cursor.lastrowid
BUT it will work ONLY if you insert a single row with execute. It will return None if you try to use it after a executemany.
If you are trying to get multiple ids of rows that were inserted at the same time see that answer that may help you.
I have a SQL Server database that has a table that lists other tables along with some meta data on them. I can pull this out through Python into a List. What I want to do then though is query each table for the number of rows in it and then append the result into my list.
So for example, I run the first part of the script and I get a List of items, each one containing a list of 3 items (name,activity, Table Name). I then want to cycle through my list, pick up the third item, use it in my SQL query and then append the result into a 4th item in the list.
It starts off
[[table1, act1, Table_1],[table2, act2, Table_2],[table3, act3, Table_3]]
The second part, first takes Table_1, counts the rows and then appends it the list
[[table1, act1, Table_1,10],[table2, act2, Table_2],[table3, act3, Table_3]]
and then for list 2 etc
[[table1, act1, Table_1,10],[table2, act2, Table_2,16],[table3, act3, Table_3]]
Tried a few things but not got any further!
Thanks in advance.
import pyodbc
conn = pyodbc.connect(connetStr)
cursor = conn.cursor()
wffList=[]
cursor.execute('SELECT C_NAME,C_ACTIVE, C_TABLE_NAME from T_FORM_HEAD')
for row in cursor:
wffList.append(row)
for row in wffList:
tabName=row[2]
quer=('SELECT Count(*) FROM '+ tabName)
cursor.execute(quer)
rowCount=cursor.fetchone()
You can creat new list and append row with all four values
new_results = []
for row in wffList:
tabName = row[2]
quer = ('SELECT Count(*) FROM '+ tabName)
cursor.execute(quer)
rowCount = cursor.fetchone()
row.append(rowCount)
new_results.append(row)
print(new_results)
Or you can use enumerate to get row's number
for number, row in enumerate(wffList):
tabName = row[2]
quer = ('SELECT Count(*) FROM '+ tabName)
cursor.execute(quer)
rowCount = cursor.fetchone()
wffList[number].append(rowCount)
print(wfflist)
But probably you could also write one SQL query to get all at once.
But it could be to complex for me at this moment.
New to python, trying to use psycopg2 to read Postgres
I am reading from a database table called deployment and trying to handle a Value from a table with three fields id, Key and Value
import psycopg2
conn = psycopg2.connect(host="localhost",database=database, user=user, password=password)
cur = conn.cursor()
cur.execute("SELECT \"Value\" FROM deployment WHERE (\"Key\" = 'DUMPLOCATION')")
records = cur.fetchall()
print(json.dumps(records))
[["newdrive"]]
I want this to be just "newdrive" so that I can do a string comparison in the next line to check if its "newdrive" or not
I tried json.loads on the json.dumps output, didn't work
>>> a=json.loads(json.dumps(records))
>>> print(a)
[['newdrive']]
I also tried to print just the records without json.dump
>>> print(records)
[('newdrive',)]
The result of fetchall() is a sequence of tuples. You can loop over the sequence and print the first (index 0) element of each tuple:
cur.execute("SELECT \"Value\" FROM deployment WHERE (\"Key\" = 'DUMPLOCATION')")
records = cur.fetchall()
for record in records:
print(record[0])
Or simpler, if you are sure the query returns no more than one row, use fetchone() which gives a single tuple representing returned row, e.g.:
cur.execute("SELECT \"Value\" FROM deployment WHERE (\"Key\" = 'DUMPLOCATION')")
row = cur.fetchone()
if row: # check whether the query returned a row
print(row[0])
I am having a hard time converting data. I select the data from my database, which is returned in tuple format. I try to convert them using list(), but all I get is a list of tuples. I am trying to compare them to integers which i receive from parsing my JSON. What would be the easiest way to convert and compare these two?
from DBConnection import db
import pymssql
from data import JsonParse
db.execute('select id from party where partyid = 1')
parse = JsonParse.Parse()
for row in cursor:
curList = list(cursor)
i = 0
for testData in parse:
print curList[i], testData['data']
i += 1
Output:
(6042,) 6042
(6043,) 6043
(6044,) 6044
(6045,) 6045
SQL results always come as rows, which are sequences of columns; this is true even if there is just one column in each row.
Next, you are executing the query on the db object (whatever that may be), but are iterating over the cursor; if this works at all is more down to luck. You'd normally execute a query on the cursor object.
If you expect just one row to be returned, you can use cursor.fetchone() to retrieve that one row. Your for row in cursor loop is actually skipping the first row.
You could use:
cursor = connection.cursor()
cursor.execute('select id from party where partyid = 1')
result = cursor.fetchone()[0]
to retrieve the first column of the first row, or you could use tuple assignment:
cursor = connection.cursor()
cursor.execute('select id from party where partyid = 1')
result, = cursor.fetchone()
If you do need to match against multiple rows, you could use a list comprehension to extract all those id columns:
cursor = connection.cursor()
cursor.execute('select id from party where partyid = 1')
result = [row[0] for row in cursor]
Now you have a list of id values.
Quick and dirty:
print curList[i][0], testData['data']
Or how about:
for db_tuple, json_int in zip(cursor, parse):
print db_tuple[0], json_int