Redesigned the user interface #23

app/db_queries.py

@@ -0,0 +1,140 @@
+#from datetime import datetime
+
+from django.conf import settings
+from django.db import connection
+
+from .models import Order
+
+
+def _db_select(sql_select:str):
+    result = None
+    with connection.cursor() as cursor:
+        cursor.execute(sql_select)
+        result = cursor.fetchall()
+    return result
+
+
+COMBINE_ALPHABET = "abcdefghijklmnopqrstuvwxyz"
+def _combine_results(results:list) -> dict:
+    '''
+    e.g.
+    input: [
+        [("x", 12), ("y", 13)],
+        [("y", 10), ("z", 42)]
+    ]
+    output: {
+        "x": {"a": 12},
+        "y": {"a": 13, "b": 10},
+        "z": {"b": 42}
+    }
+    '''
+    result = {}
+    for i, d in enumerate(results):
+        a = COMBINE_ALPHABET[i]
+        for r in d:
+            r_0 = r[0]
+            if r_0 not in result:
+                result[r_0] = {}
+            result[r_0][a] = r[1]
+    return result
+
+
+def select_history(user, language_code="en") -> list:
+    # select order history and deposits
+    user_id = user.pk
+    result = _db_select(f"""
+    select
+        concat(
+        product_name, ' (',
+        content_litres::real, -- converting to real removes trailing zeros
+        'l) x ', amount, ' - ', price_sum, '{settings.CURRENCY_SUFFIX}') as "text",
+        datetime
+    from app_order
+    where user_id = {user_id}
+
+    union 
+
+    select
+        concat('Deposit: +', transaction_sum, '{settings.CURRENCY_SUFFIX}') as "text",
+        datetime
+    from app_userdeposits_view
+    where user_id = {user_id}
+
+    order by datetime desc
+    fetch first 30 rows only;
+    """)
+    result = [list(row) for row in result]
+    if language_code == "de": # reformat for german translation
+        for row in result:
+            row[0] = row[0].replace(".", ",")
+    return result
+
+
+def orders_per_month(user) -> list:
+    # number of orders per month (last 12 months)
+    result_user = _db_select(f"""
+    select
+        to_char(date_trunc('month', datetime), 'YYYY-MM') as "month",
+        sum(amount) as "count"
+    from app_order
+        where user_id = {user.pk}
+        and date_trunc('month', datetime) > date_trunc('month', now() - '12 months'::interval)
+    group by "month"
+    order by "month" desc;
+    """)
+    result_all = _db_select(f"""
+    select
+        to_char(date_trunc('month', datetime), 'YYYY-MM') as "month",
+        sum(amount) as "count"
+    from app_order
+        where date_trunc('month', datetime) > date_trunc('month', now() - '12 months'::interval)
+    group by "month"
+    order by "month" desc;
+    """)
+    return _combine_results([result_user, result_all])
+
+
+def orders_per_weekday(user) -> list:
+    # number of orders per weekday (all time)
+    result_user = _db_select(f"""
+    select
+        to_char(datetime, 'Day') as "day",
+        sum(amount) as "count"
+    from app_order
+        where user_id = {user.pk}
+    group by "day"
+    order by "count" desc;
+    """)
+    result_all = _db_select(f"""
+    select
+        to_char(datetime, 'Day') as "day",
+        sum(amount) as "count"
+    from app_order
+    group by "day"
+    order by "count" desc;
+    """)
+    return _combine_results([result_user, result_all])
+
+
+def orders_per_drink(user) -> list:
+    # number of orders per drink (all time)
+    result_user = _db_select(f"""
+    select
+        d.product_name as "label",
+        sum(o.amount) as "data"
+    from app_drink d
+        join app_order o on (d.id = o.drink_id)
+    where o.user_id = {user.pk}
+    group by d.product_name
+    order by "data" desc;
+    """)
+    result_all = _db_select(f"""
+    select
+        d.product_name as "label",
+        sum(o.amount) as "data"
+    from app_drink d
+        join app_order o on (d.id = o.drink_id)
+    group by d.product_name
+    order by "data" desc;
+    """)
+    return _combine_results([result_user, result_all])