Develop Reference

Get all data API when inputs are empty

I created my first API where I can get data from my tables in Bigquery.
I can get all the data I need based on the 2 inputs below, but I am also trying to get the whole table when the inputs are empty, which I cannot do.
Thanks for your help
#app.route("/tracking", methods=['GET'])
def tracking_data():
haulier_id_tracking = request.args.get('haulier_id_tracking')
month_tracking = request.args.get('month_tracking')
query_job = bq_client.query("""
WITH t AS (
SELECT *
FROM mart.monthly_vehicle_stats
WHERE dt_fr_month = '{month_tracking}-01' AND (haulier_id_tracking = '{haulier_id_tracking}')
SELECT TO_JSON_STRING(STRUCT(ARRAY_AGG(STRUCT(dt_fr_month, haulier_id_tracking, vehicle_id , nb_days_tracked,
data_access, date_first_camp, invoiced)) AS data)) json
FROM t
""".format(month_tracking = month_tracking, haulier_id_tracking = haulier_id_tracking))
for row in query_job:
return json.loads(row["json"])

You can remove the where clause when the input is empty like this:
#app.route("/tracking", methods=['GET'])
def tracking_data():
haulier_id_tracking = request.args.get('haulier_id_tracking')
month_tracking = request.args.get('month_tracking')
where_clause = ''
if haulier_id_tracking != '' and month_tracking != '':
where_clause = f"WHERE dt_fr_month = '{month_tracking}-01' AND (haulier_id_tracking = '{haulier_id_tracking}'"
query_job = bq_client.query(f"""
WITH t AS (
SELECT * FROM mart.monthly_vehicle_stats {where_clause})
SELECT TO_JSON_STRING(STRUCT(ARRAY_AGG(STRUCT(dt_fr_month, haulier_id_tracking, vehicle_id , nb_days_tracked,
data_access, date_first_camp, invoiced)) AS data)) json
FROM t
""")
for row in query_job:
return json.loads(row["json"])

Return Missing Rows from Python SQL Query

Is there anyway i can compare two different databases (postgresl, sql server) and return the missing rows? I am missing one row in the postgresql table that is not in the sql server one and have no clue how to return that answer to me.
I have two connections opened for postgresql (bpo_table_results) and for sql server(rps_table_results)
postgresql table:
date count amount
1/1/21 500 1,234,654.12
sql server table:
date count amount
1/1/21 500 1,234,654.12
1/2/21 4541 3,457,787.24
expected results:
The row in the amount of 3,457,787.24 is missing from your posgresql table.
code:
def queryRPS(sql_server_conn, sql_server_cursor):
rps_item_count_l = []
rps_icl_amt_l = []
rps_table_q_2 = f"""select * from rps..sendfile where processingdate = '{cd}' and datasetname like '%ICL%' """
rps_table_results = sql_server_cursor.execute(rps_table_q_2).fetchall()
for row in rps_table_results:
rps_item_count = row[16]
rps_item_count_l.append(rps_item_count)
rps_icl_amt = row[18]
rps_icl_amt_l.append(rps_icl_amt)
def queryBPO(postgres_conn, postgres_cursor,rps_item_count_l, rps_icl_amt_l):
bpo_results_l = []
rps_results_l = []
for rps_count, rps_amount in zip(rps_item_count_l, rps_icl_amt_l):
rps_amount_f = str(rps_amount).rstrip('0')
rps_amount_f = ("{:,}".format(float(rps_amount_f)))
bpo_icl_awk_q_2 = """select * from ppc_data.icl_awk where num_items = '%s' and
file_total = '%s' """ % (str(rps_count), str(rps_amount_f))
postgres_cursor.execute(bpo_icl_awk_q_2)
bpo_table_results = postgres_cursor.fetchall()
rps_table_q_2 = f"""select * from rps..sendfile where processingdate = '{cd}' and datasetname like '%ICL%' """
rps_table_results = sql_server_cursor.execute(rps_table_q_2).fetchall()
rps_item_count_l, rps_icl_amt_l = queryRPS(sql_server_conn, sql_server_cursor)
queryBPO(postgres_conn, postgres_cursor, rps_item_count_l, rps_icl_amt_l)

How to pass value of variable into another text file?

I have text files which have sql queries.After running one file "tb_exec_ns_call_pln.txt" i'm getting two dates like- 2018-12-29 ,
2019-03-29.
i just want to pass these dates in other text file (tb_exec_ns_call_actvty.txt) using python. the text file contain the below query-
SELECT a.nm as cycle_nm,
a.start_dt as cycle_start_dt,
a.end_dt as cycle_end_dt,
a.terr as territory,sales_drctn,
x_rating1,
c.jnj_id as jnj_id,
c.prsn_first_nm,
c.prsn_last_nm,
plnnd_calls as rep_goal
FROM eureka.cycle_plan a, eureka.cycle_plan_trgt b, eureka.acct c
WHERE
a.id = b.cycle_plan
and b.acct = c.id
and b.del_flg = 'N'
***and start_dt >= '2018-12-29'***
***and end_dt <= '2019-03-29'***
and substring(a.terr,1,6) in ('106-KS','106-PI','106-VO')
and a.status = 'In_Progress_vod'
and a.del_flg = 'N'
and c.del_flg = 'N' and plnnd_calls > 0
i have written python script also.. Please guide me how to pass the value.
path = "D:/Users/SPate233/Downloads/NS dashboard/tb_exec_ns_call_pln.txt"
sql_query_file = open(path, 'r')
sql_query1 = sql_query_file.read()
cur.execute(sql_query1)
res = cur.fetchall()
print(res)
print(type(res))
for val in res:
print(val[1])
print(val[2])

One approach is to have a string variable hardcoded in to tb_exec_ns_call_actvty.txt and then use str.replace to fill in the required info.
Ex:
SELECT a.nm as cycle_nm,
a.start_dt as cycle_start_dt,
a.end_dt as cycle_end_dt,
a.terr as territory,sales_drctn,
x_rating1,
c.jnj_id as jnj_id,
c.prsn_first_nm,
c.prsn_last_nm,
plnnd_calls as rep_goal
FROM eureka.cycle_plan a, eureka.cycle_plan_trgt b, eureka.acct c
WHERE
a.id = b.cycle_plan
and b.acct = c.id
and b.del_flg = 'N'
and start_dt >= 'START_DT'
and end_dt <= 'END_DT'
and substring(a.terr,1,6) in ('106-KS','106-PI','106-VO')
and a.status = 'In_Progress_vod'
and a.del_flg = 'N'
and c.del_flg = 'N' and plnnd_calls > 0
InCode:
path = "D:/Users/SPate233/Downloads/NS dashboard/tb_exec_ns_call_pln.txt"
with open(path) as sql_query_file:
sql_query1 = sql_query_file.read()
sql_query1 = sql_query1.replace("START_DT", '2018-12-29').replace("END_DT", '2019-03-29')
cur.execute(sql_query1)
res = cur.fetchall()

Panda DataFrame Row Items IF Comparison doesnt return correct result

I retrieve data from quandl and load it to a pandas DF object.
Afterwards I calculate SMA values (SMA21, SMA55) based on "Last Price".
Adding those SMA values as a column do my DF object.
I iterate through DF to catch a buy signal.
I know the buy condition is holding true for some dates but my code does not printing anything out. I am expecting to print the buy condition at the very least.
as below you can see the following condition:
kitem['SMA21'] >= kitem['Last']
My code:
import requests
import pandas as pd
import json
class URL_Params:
def __init__ (self, endPoint, symboll, startDate, endDate, apiKey):
self.endPoint = endPoint
self.symboll = symboll
self.startDate = startDate
self.endDate = endDate
self.apiKey = apiKey
def createURL (self):
return self.endPoint + self.symboll + '?start_date=' + self.startDate + '&end_date=' + self.endDate + '&api_key=' + self.apiKey
def add_url(self, _url):
self.url_list
my_portfolio = {'BTC':1.0, 'XRP':0, 'DSH':0, 'XMR':0, 'TotalBTCValue':1.0}
_endPoint = 'https://www.quandl.com/api/v3/datasets/BITFINEX/'
_symbolls = ['BTCEUR','XRPBTC','DSHBTC','IOTBTC','XMRBTC']
_startDate = '2017-01-01'
_endDate = '2019-03-01'
_apiKey = '' #needs to be set for quandl
my_data = {}
my_conns = {}
my_col_names = ['Date', 'High', 'Low', 'Mid', 'Last', 'Bid', 'Ask', 'Volume']
orderbook = []
#create connection and load data for each pair/market.
#load them in a dict for later use
for idx_symbol in _symbolls:
my_url_params = URL_Params(_endPoint,idx_symbol,_startDate,_endDate,_apiKey)
response = requests.get(my_url_params.createURL())
my_data[idx_symbol] = json.loads(response.text)
#Prepare Data
my_raw_data_df_xrpbtc = pd.DataFrame(my_data['XRPBTC']['dataset']['data'], columns= my_data['XRPBTC']['dataset']['column_names'])
#Set Index to Date Column and Sort
my_raw_data_df_xrpbtc['Date'] = pd.to_datetime(my_raw_data_df_xrpbtc['Date'])
my_raw_data_df_xrpbtc.index = my_raw_data_df_xrpbtc['Date']
my_raw_data_df_xrpbtc = my_raw_data_df_xrpbtc.sort_index()
#Drop unrelated columns
my_raw_data_df_xrpbtc.drop(['Date'], axis=1, inplace=True)
my_raw_data_df_xrpbtc.drop(['Ask'], axis=1, inplace=True)
my_raw_data_df_xrpbtc.drop(['Bid'], axis=1, inplace=True)
my_raw_data_df_xrpbtc.drop(['Low'], axis=1, inplace=True)
my_raw_data_df_xrpbtc.drop(['High'], axis=1, inplace=True)
my_raw_data_df_xrpbtc.drop(['Mid'], axis=1, inplace=True)
#Calculate SMA values to create buy-sell signal
my_raw_data_df_xrpbtc['SMA21'] = my_raw_data_df_xrpbtc['Last'].rolling(21).mean()
my_raw_data_df_xrpbtc['SMA55'] = my_raw_data_df_xrpbtc['Last'].rolling(55).mean()
my_raw_data_df_xrpbtc['SMA200'] = my_raw_data_df_xrpbtc['Last'].rolling(200).mean()
#Check for each day if buy signal holds BUY if sell signal holds SELL
for idx,kitem in my_raw_data_df_xrpbtc.iterrows():
if (kitem['SMA21'] >= kitem['Last']) is True: #buy signal
print("buy0")
if my_portfolio['BTC'] > 0 is True:
print("buy1")
if (kitem['Last'] * my_portfolio['XRP']) >= (my_portfolio['BTC'] * 1.05) is True: #sell signal
print("sell0")
if my_portfolio['XRP'] > 0 is True:
print("sell1")
I know that there are lots of rows that holds true but my code never enters this path of code so it does not print out what I expect.
Could anyone please help/comment what might be wrong?

The reason is that your comparison is wrong. The result of kitem['SMA21'] >= kitem['Last'] will be a numpy.bool_. When you use is to compare it to True this will fail as it is not the same object.
If you change the comparison to == it will work as expected:
if (kitem['SMA21'] >= kitem['Last']) == True:

Build a dynamic update query in psycopg2

I have to construct a dynamic update query for postgresql.
Its dynamic, because beforehand I have to determine which columns to update.
Given a sample table:
create table foo (id int, a int, b int, c int)
Then I will construct programmatically the "set" clause
_set = {}
_set['a'] = 10
_set['c'] = NULL
After that I have to build the update query. And here I'm stuck.
I have to construct this sql Update command:
update foo set a = 10, b = NULL where id = 1
How to do this with the psycopg2 parametrized command? (i.e. looping through the dict if it is not empty and build the set clause) ?
UPDATE
While I was sleeping I have found the solution by myself. It is dynamic, exactly how I wanted to be :-)
create table foo (id integer, a integer, b integer, c varchar)
updates = {}
updates['a'] = 10
updates['b'] = None
updates['c'] = 'blah blah blah'
sql = "upgrade foo set %s where id = %s" % (', '.join("%s = %%s" % u for u in updates.keys()), 10)
params = updates.values()
print cur.mogrify(sql, params)
cur.execute(sql, params)
And the result is what and how I needed (especially the nullable and quotable columns):
"upgrade foo set a = 10, c = 'blah blah blah', b = NULL where id = 10"

There is actually a slightly cleaner way to make it, using the alternative column-list syntax:
sql_template = "UPDATE foo SET ({}) = %s WHERE id = {}"
sql = sql_template.format(', '.join(updates.keys()), 10)
params = (tuple(addr_dict.values()),)
print cur.mogrify(sql, params)
cur.execute(sql, params)

Using psycopg2.sql – SQL string composition module
The module contains objects and functions useful to generate SQL dynamically, in a convenient and safe way.
from psycopg2 import connect, sql
conn = connect("dbname=test user=postgres")
upd = {'name': 'Peter', 'age': 35, 'city': 'London'}
ref_id = 12
sql_query = sql.SQL("UPDATE people SET {data} WHERE id = {id}").format(
data=sql.SQL(', ').join(
sql.Composed([sql.Identifier(k), sql.SQL(" = "), sql.Placeholder(k)]) for k in upd.keys()
),
id=sql.Placeholder('id')
)
upd.update(id=ref_id)
with conn:
with conn.cursor() as cur:
cur.execute(sql_query, upd)
conn.close()
Running print(sql_query.as_string(conn)) before closing connection will reveal this output:
UPDATE people SET "name" = %(name)s, "age" = %(age)s, "city" = %(city)s WHERE id = %(id)s

No need for dynamic SQL. Supposing a is not nullable and b is nullable.
If you want to update both a and b:
_set = dict(
id = 1,
a = 10,
b = 20, b_update = 1
)
update = """
update foo
set
a = coalesce(%(a)s, a), -- a is not nullable
b = (array[b, %(b)s])[%(b_update)s + 1] -- b is nullable
where id = %(id)s
"""
print cur.mogrify(update, _set)
cur.execute(update, _set)
Output:
update foo
set
a = coalesce(10, a), -- a is not nullable
b = (array[b, 20])[1 + 1] -- b is nullable
where id = 1
If you want to update none:
_set = dict(
id = 1,
a = None,
b = 20, b_update = 0
)
Output:
update foo
set
a = coalesce(NULL, a), -- a is not nullable
b = (array[b, 20])[0 + 1] -- b is nullable
where id = 1

An option without python format using psycopg2's AsIs function for column names (although that doesn't prevent you from SQL injection over column names). Dict is named data:
update_statement = f'UPDATE foo SET (%s) = %s WHERE id_column=%s'
columns = data.keys()
values = [data[column] for column in columns]
query = cur.mogrify(update_statement, (AsIs(','.join(columns)), tuple(values), id_value))

Here's my solution that I have within a generic DatabaseHandler class that provides a lot of flexibility when using pd.DataFrame as your source.
def update_data(
self,
table: str,
df: pd.DataFrame,
indexes: Optional[list] = None,
column_map: Optional[dict] = None,
commit: Optional[bool] = False,
) -> int:
"""Update data in the media database
Args:
table (str): the "tablename" or "namespace.tablename"
df (pandas.DataFrame): dataframe containing the data to update
indexes (list): the list of columns in the table that will be in the WHERE clause of the update statement.
If not provided, will use df indexes.
column_map (dict): dictionary mapping the columns in df to the columns in the table
columns in the column_map that are also in keys will not be updated
Key = df column.
Value = table column.
commit (bool): if True, the transaction will be committed (default=False)
Notes:
If using a column_map, only the columns in the data_map will be updated or used as indexes.
Order does not matter. If not using a column_map, all columns in df must exist in table.
Returns:
int : rows updated
"""
try:
if not indexes:
# Use the dataframe index instead
indexes = []
for c in df.index.names:
if not c:
raise Exception(
f"Dataframe contains indexes without names. Unable to determine update where clause."
)
indexes.append(c)
update_strings = []
tdf = df.reset_index()
if column_map:
target_columns = [c for c in column_map.keys() if c not in indexes]
else:
column_map = {c: c for c in tdf.columns}
target_columns = [c for c in df.columns if c not in indexes]
for i, r in tdf.iterrows():
upd_params = ", ".join(
[f"{column_map[c]} = %s" for c in target_columns]
)
upd_list = [r[c] if pd.notna(r[c]) else None for c in target_columns]
upd_str = self._cur.mogrify(upd_params, upd_list).decode("utf-8")
idx_params = " AND ".join([f"{column_map[c]} = %s" for c in indexes])
idx_list = [r[c] if pd.notna(r[c]) else None for c in indexes]
idx_str = self._cur.mogrify(idx_params, idx_list).decode("utf-8")
update_strings.append(f"UPDATE {table} SET {upd_str} WHERE {idx_str};")
full_update_string = "\n".join(update_strings)
print(full_update_string) # Debugging
self._cur.execute(full_update_string)
rowcount = self._cur.rowcount
if commit:
self.commit()
return rowcount
except Exception as e:
self.rollback()
raise e
Example usages:
>>> df = pd.DataFrame([
{'a':1,'b':'asdf','c':datetime.datetime.now()},
{'a':2,'b':'jklm','c':datetime.datetime.now()}
])
>>> cls.update_data('my_table', df, indexes = ['a'])
UPDATE my_table SET b = 'asdf', c = '2023-01-17T22:13:37.095245'::timestamp WHERE a = 1;
UPDATE my_table SET b = 'jklm', c = '2023-01-17T22:13:37.095250'::timestamp WHERE a = 2;
>>> cls.update_data('my_table', df, indexes = ['a','b'])
UPDATE my_table SET c = '2023-01-17T22:13:37.095245'::timestamp WHERE a = 1 AND b = 'asdf';
UPDATE my_table SET c = '2023-01-17T22:13:37.095250'::timestamp WHERE a = 2 AND b = 'jklm';
>>> cls.update_data('my_table', df.set_index('a'), column_map={'a':'db_a','b':'db_b','c':'db_c'} )
UPDATE my_table SET db_b = 'asdf', db_c = '2023-01-17T22:13:37.095245'::timestamp WHERE db_a = 1;
UPDATE my_table SET db_b = 'jklm', db_c = '2023-01-17T22:13:37.095250'::timestamp WHERE db_a = 2;
Note however that this is not safe from SQL injection due to the way it generates the where clause.