Add a debug comment to first line of SQL

This makes it easier to see what the queries are from

Author: pnorman

tests/test_config.py

@@ -170,13 +170,13 @@ def test_render(self):
             self.assertIsNone(layer.render_sql(Tile(5, 0, 0)))
             self.assertIsNone(layer.render_sql(Tile(7, 0, 0)))
 
-            self.assertEqual(layer.render_sql(Tile(4, 0, 0)), '''WITH mvtgeom AS
+            self.assertEqual(layer.render_sql(Tile(4, 0, 0)), '''WITH mvtgeom AS -- foo/4/0/0
 (
 one
 )
 SELECT ST_AsMVT(mvtgeom.*, 'foo', 4096)
 FROM mvtgeom;''')
-            self.assertEqual(layer.render_sql(Tile(6, 0, 0)), '''WITH mvtgeom AS
+            self.assertEqual(layer.render_sql(Tile(6, 0, 0)), '''WITH mvtgeom AS -- foo/6/0/0
 (
 two
 )

tests/test_definition.py

@@ -45,7 +45,7 @@ def test_render(self):
             fs.writetext("one.sql.jinja2", "SELECT 1")
             d = Definition("one", {"minzoom": 1, "maxzoom": 3, "extent": 1024, "buffer": 8,
                                    "file": "one.sql.jinja2"}, fs)
-            expected = '''WITH mvtgeom AS
+            expected = '''WITH mvtgeom AS -- one/2/0/0
 (
 SELECT 1
 )
@@ -57,7 +57,7 @@ def test_render(self):
                                            "{{unbuffered_bbox}}\n{{extent}}\n{{buffer}}")
             d = Definition("two", {"minzoom": 1, "maxzoom": 3, "extent": 1024, "buffer": 256,
                                    "file": "two.sql.jinja2"}, fs)
-            expected = '''WITH mvtgeom AS
+            expected = '''WITH mvtgeom AS -- two/2/0/1
 (
 SELECT 2/0/1
 ST_TileEnvelope(2, 0, 1, margin=>0.25)
@@ -74,7 +74,7 @@ def test_render(self):
             d = Definition("units", {"minzoom": 1, "maxzoom": 3, "extent": 1024, "buffer": 256,
                                      "file": "units.sql.jinja2"}, fs)
             # Crudely slice up the string to turn it into numbers
-            expected = '''WITH mvtgeom AS
+            expected = '''WITH mvtgeom AS -- units/2/0/1
 (
 10018754.17
 100375435118892.39
@@ -89,7 +89,7 @@ def test_render(self):
             d = Definition("whitespace", {"minzoom": 1, "maxzoom": 3, "extent": 1024, "buffer": 256,
                                           "file": "whitespace.sql.jinja2"}, fs)
             # Crudely slice up the string to turn it into numbers
-            expected = '''WITH mvtgeom AS
+            expected = '''WITH mvtgeom AS -- whitespace/2/0/1
 (
 foo
 bar

tilekiln/definition.py

@@ -58,8 +58,8 @@ def render_sql(self, tile: Tile) -> str:
                                        coordinate_area=(tile_length(tile)/self.extent)**2)
 
         # TODO: Use proper escaping for self.id in SQL
-        return ('''WITH mvtgeom AS\n(\n''' + inner + '''\n)\n''' +
-                f'''SELECT ST_AsMVT(mvtgeom.*, '{self.id}', {self.extent})\n''' +
+        return (f'''WITH mvtgeom AS -- {self.id}/{tile.zoom}/{tile.x}/{tile.y}\n(\n''' +
+                inner + f'''\n)\nSELECT ST_AsMVT(mvtgeom.*, '{self.id}', {self.extent})\n''' +
                 '''FROM mvtgeom;''')