db: Create a YearTable and Year object

I do lookups and inserts based only on the year field. Decades are
created automatically on insert.

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

db/__init__.py

@@ -16,9 +16,10 @@ from . import album
 from . import disc
 from . import genre
 from . import decade
+from . import year
 
 def reset():
-    mods = [ artist, album, disc, genre, decade ]
+    mods = [ artist, album, disc, genre, decade, year ]
 
     for mod in mods: mod.Table.drop()
     for mod in mods: mod.Table.do_create()

db/test_year.py

@@ -0,0 +1,53 @@
+# Copyright 2021 (c) Anna Schumaker.
+import db
+import sqlite3
+import unittest
+from gi.repository import GObject
+
+
+class TestYearTable(unittest.TestCase):
+    def setUp(self):
+        db.reset()
+
+    def test_year_table_init(self):
+        self.assertIsInstance(db.year.Table, db.year.YearTable)
+        db.execute("SELECT yearid,decadeid,year FROM years")
+
+    def test_year_table_insert(self):
+        decade = db.decade.Table.insert(2020)
+        year   = db.year.Table.insert(2021)
+
+        self.assertIsInstance(year, db.year.Year)
+        self.assertIsInstance(year, db.objects.Row)
+
+        self.assertEqual(year.year, 2021)
+        self.assertEqual(str(year), "2021")
+        self.assertEqual(year.get_property("decade"), decade)
+
+        with self.assertRaises(sqlite3.IntegrityError):
+            db.year.Table.insert(2021)
+
+    def test_year_table_delete(self):
+        year = db.year.Table.find(2021)
+        db.year.Table.delete(year)
+        self.assertIsNone(db.year.Table.lookup(2021))
+
+    def test_year_table_get(self):
+        year = db.year.Table.insert(2021)
+        self.assertEqual(db.year.Table.get(1), year)
+        self.assertIsNone(db.year.Table.get(2))
+
+    def test_year_table_lookup(self):
+        year = db.year.Table.insert(2021)
+        self.assertEqual(db.year.Table.lookup(2021), year)
+        self.assertIsNone(db.year.Table.lookup(2022))
+
+    def test_year_compare(self):
+        y2021 = db.year.Table.insert(2021)
+        y2022 = db.year.Table.insert(2022)
+
+        self.assertTrue(y2021 < y2022)
+        self.assertTrue(y2022 > y2021)
+
+        self.assertFalse(y2021 > y2022)
+        self.assertFalse(y2022 < y2021)

db/year.py

@@ -0,0 +1,58 @@
+# Copyright 2021 (c) Anna Schumaker.
+#
+# Table: years
+# +--------+----------+------+
+# | yearid | decadeid | year |
+# +--------+----------+------+
+from gi.repository import GObject
+from . import decade
+from . import execute
+from . import objects
+
+class Year(objects.Row):
+    def __gt__(self, rhs): return self.year > rhs.year
+    def __lt__(self, rhs): return self.year < rhs.year
+    def __str__(self): return str(self.year)
+
+    def do_get_column(self, column):
+        return execute(f"SELECT {column} FROM years "
+                        "WHERE yearid=?", [ self.rowid ])
+
+    @GObject.Property
+    def decade(self):
+        return decade.Decade(self.get_column("decadeid"))
+
+    @GObject.Property
+    def year(self):
+        return self.get_column("year")
+
+
+class YearTable(objects.Table):
+    def __init__(self):
+        objects.Table.__init__(self, "years", Year)
+
+    def do_create(self):
+        execute("CREATE TABLE IF NOT EXISTS years "
+                    "(yearid INTEGER PRIMARY KEY, "
+                    " decadeid INTEGER, "
+                    " year INTEGER UNIQUE, "
+                    " FOREIGN KEY(decadeid) REFERENCES decades(decadeid))")
+
+    def do_insert(self, year):
+        dec = decade.Table.find( (year // 10) * 10)
+        return execute("INSERT INTO years (decadeid, year) "
+                       "VALUES (?, ?)", (int(dec), year))
+
+    def do_delete(self, year):
+        return execute("DELETE FROM years WHERE yearid=?", [ int(year) ])
+
+    def do_get(self, rowid):
+        return execute("SELECT yearid FROM years "
+                       "WHERE yearid=?", [ rowid ])
+
+    def do_lookup(self, year):
+        return execute("SELECT yearid FROM years "
+                       "WHERE year=?", [ year ])
+
+
+Table = YearTable()