Prepare for a big db.py refactor

lib/nexrad/db.py

@@ -26,6 +26,22 @@ class DatabaseTable():
             object.__setattr__(self, '__dirty__', True)
             values[k] += 1
 
+    def __format_columns_select__(self):
+        csel = getattr(self, '__columns_select__')
+
+        if csel is None:
+            return self.__columns__
+        else:
+            ret = list()
+
+            for c in self.__columns__:
+                if c in csel:
+                    ret.append(csel[c])
+                else:
+                    ret.append(c)
+
+            return ret
+
 class DatabaseTableCursor():
     __slots__ = 'cr', 'table',
 
@@ -160,7 +176,7 @@ class Database():
         return cr
 
     def query(self, table, values=dict(), order_by=list()):
-        selectors = getattr(table, '__selectors__')
+        selectors = getattr(table, '__columns_select__')
 
         if selectors is None:
             columns = table.__columns__

lib/nexrad/storm.py

@@ -97,12 +97,12 @@ class StormReport(DatabaseTable):
         'tornado_f_rating', 'coord_start', 'coord_end'
     )
 
-    __selectors__ = {
+    __columns_select__ = {
         'coord_start': 'ST_AsText(coord_start) as coord_start',
         'coord_end':   'ST_AsText(coord_end) as coord_end'
     }
 
-    __constructors__ = {
+    __columns_insert__ = {
         'coord_start': lambda v: 'null' if v is None else f'MakePoint({v.lon}, {v.lat}, {COORD_SYSTEM})',
         'coord_end':   lambda v: 'null' if v is None else f'MakePoint({v.lon}, {v.lat}, {COORD_SYSTEM})'
     }
@@ -238,29 +238,39 @@ class StormReport(DatabaseTable):
                       coord:     Coord=None,
                       radius:    float=RADAR_RANGE,
                       timestamp: datetime.datetime=None):
-        sql = """
+        columns = StormReport.__format_columns_select__(StormReport)
-            select * from nexrad_storm_report
-        """
-
         clauses = list()
-        values  = list()
+        values  = dict()
 
         if coord is not None:
-            clauses.append("""ST_DistanceWithin(MakeLine(coord_start, coord_end),
+            columns.append("""
-                                                MakePoint(?, ?, {csr}),
+                ST_Distance(MakeLine(coord_start, coord_end),
-                                                {radius}) = 1""".format(
+                            MakePoint(:lon, :lat, :crs),
-                csr    = COORD_SYSTEM,
+                            true) as distance
-                radius = radius
+            """)
-            ))
 
-            values.append(coord.lon)
+            clauses.extend([
-            values.append(coord.lat)
+                'distance <= :radius'
+            ])
+
+            values.update({
+                'lon':    coord.lon,
+                'lat':    coord.lat,
+                'crs':    COORD_SYSTEM,
+                'radius': radius
+            })
 
         if timestamp is not None:
-            clauses.append("timestamp_start >= ? and timestamp_end <= ?")
+            clauses.append("timestamp_start >= :timestamp and timestamp_end <= :timestamp")
+
+            values.update({
+                'timestamp': timestamp.isoformat()
+            })
 
             values.append(timestamp.isoformat())
 
+        sql = "select " + ", ".join(columns) + " from nexrad_storm_report"
+
         if len(clauses) > 0:
             sql += " where " + " and ".join(clauses)
 
@@ -268,7 +278,6 @@ class StormReport(DatabaseTable):
 
         while True:
             obj = st.fetchone()
-
             if obj is None:
                 break