New ?tags__arraycontains=tag lookup against JSON fields

Part one of supporting facet-by-JSON-array, refs #359

datasette/utils.py

@@ -565,6 +565,16 @@ def detect_fts_sql(table):
     '''.format(table=table)
 
 
+def detect_json1(conn=None):
+    if conn is None:
+        conn = sqlite3.connect(":memory:")
+    try:
+        conn.execute("SELECT json('{}')")
+        return True
+    except Exception:
+        return False
+
+
 def table_columns(conn, table):
     return [
         r[1]
@@ -584,7 +594,7 @@ class Filter:
         self.numeric = numeric
         self.no_argument = no_argument
 
-    def where_clause(self, column, value, param_counter):
+    def where_clause(self, table, column, value, param_counter):
         converted = self.format.format(value)
         if self.numeric and converted.isdigit():
             converted = int(converted)
@@ -597,6 +607,7 @@ class Filter:
             kwargs = {
                 'c': column,
                 'p': 'p{}'.format(param_counter),
+                't': table,
             }
         return self.sql_template.format(**kwargs), converted
 
@@ -613,6 +624,7 @@ class Filter:
 
 class Filters:
     _filters = [
+        # key, display, sql_template, human_template, format=, numeric=, no_argument=
         Filter('exact', '=', '"{c}" = :{p}', lambda c, v: '{c} = {v}' if v.isdigit() else '{c} = "{v}"'),
         Filter('not', '!=', '"{c}" != :{p}', lambda c, v: '{c} != {v}' if v.isdigit() else '{c} != "{v}"'),
         Filter('contains', 'contains', '"{c}" like :{p}', '{c} contains "{v}"', format='%{}%'),
@@ -624,6 +636,11 @@ class Filters:
         Filter('lte', '\u2264', '"{c}" <= :{p}', '{c} \u2264 {v}', numeric=True),
         Filter('glob', 'glob', '"{c}" glob :{p}', '{c} glob "{v}"'),
         Filter('like', 'like', '"{c}" like :{p}', '{c} like "{v}"'),
+    ] + ([Filter('arraycontains', 'array contains', """rowid in (
+            select {t}.rowid from {t}, json_each({t}.{c}) j
+            where j.value = :{p}
+        )""", '{c} contains "{v}"')
+    ] if detect_json1() else []) + [
         Filter('isnull', 'is null', '"{c}" is null', '{c} is null', no_argument=True),
         Filter('notnull', 'is not null', '"{c}" is not null', '{c} is not null', no_argument=True),
         Filter('isblank', 'is blank', '("{c}" is null or "{c}" = "")', '{c} is blank', no_argument=True),
@@ -677,7 +694,7 @@ class Filters:
         return bool(self.pairs)
 
     def convert_unit(self, column, value):
-        "If the user has provided a unit in the quey, convert it into the column unit, if present."
+        "If the user has provided a unit in the query, convert it into the column unit, if present."
         if column not in self.units:
             return value
 
@@ -690,13 +707,13 @@ class Filters:
         column_unit = self.ureg(self.units[column])
         return value.to(column_unit).magnitude
 
-    def build_where_clauses(self):
+    def build_where_clauses(self, table):
         sql_bits = []
         params = {}
         for i, (column, lookup, value) in enumerate(self.selections()):
             filter = self._filters_by_key.get(lookup, None)
             if filter:
-                sql_bit, param = filter.where_clause(column, self.convert_unit(column, value), i)
+                sql_bit, param = filter.where_clause(table, column, self.convert_unit(column, value), i)
                 sql_bits.append(sql_bit)
                 if param is not None:
                     param_id = 'p{}'.format(i)

datasette/views/table.py

@@ -293,7 +293,7 @@ class TableView(RowTableShared):
         table_metadata = self.ds.table_metadata(database, table)
         units = table_metadata.get("units", {})
         filters = Filters(sorted(other_args.items()), units, ureg)
-        where_clauses, params = filters.build_where_clauses()
+        where_clauses, params = filters.build_where_clauses(table)
 
         # _search support:
         fts_table = await self.ds.execute_against_connection_in_thread(

tests/fixtures.py

@@ -523,26 +523,27 @@ CREATE TABLE facetable (
     state text,
     city_id integer,
     neighborhood text,
+    tags text,
     FOREIGN KEY ("city_id") REFERENCES [facet_cities](id)
 );
 INSERT INTO facetable
-    (planet_int, on_earth, state, city_id, neighborhood)
+    (planet_int, on_earth, state, city_id, neighborhood, tags)
 VALUES
-    (1, 1, 'CA', 1, 'Mission'),
-    (1, 1, 'CA', 1, 'Dogpatch'),
-    (1, 1, 'CA', 1, 'SOMA'),
-    (1, 1, 'CA', 1, 'Tenderloin'),
-    (1, 1, 'CA', 1, 'Bernal Heights'),
-    (1, 1, 'CA', 1, 'Hayes Valley'),
-    (1, 1, 'CA', 2, 'Hollywood'),
-    (1, 1, 'CA', 2, 'Downtown'),
-    (1, 1, 'CA', 2, 'Los Feliz'),
-    (1, 1, 'CA', 2, 'Koreatown'),
-    (1, 1, 'MI', 3, 'Downtown'),
-    (1, 1, 'MI', 3, 'Greektown'),
-    (1, 1, 'MI', 3, 'Corktown'),
-    (1, 1, 'MI', 3, 'Mexicantown'),
-    (2, 0, 'MC', 4, 'Arcadia Planitia')
+    (1, 1, 'CA', 1, 'Mission', '["tag1", "tag2"]'),
+    (1, 1, 'CA', 1, 'Dogpatch', '["tag1", "tag3"]'),
+    (1, 1, 'CA', 1, 'SOMA', '[]'),
+    (1, 1, 'CA', 1, 'Tenderloin', '[]'),
+    (1, 1, 'CA', 1, 'Bernal Heights', '[]'),
+    (1, 1, 'CA', 1, 'Hayes Valley', '[]'),
+    (1, 1, 'CA', 2, 'Hollywood', '[]'),
+    (1, 1, 'CA', 2, 'Downtown', '[]'),
+    (1, 1, 'CA', 2, 'Los Feliz', '[]'),
+    (1, 1, 'CA', 2, 'Koreatown', '[]'),
+    (1, 1, 'MI', 3, 'Downtown', '[]'),
+    (1, 1, 'MI', 3, 'Greektown', '[]'),
+    (1, 1, 'MI', 3, 'Corktown', '[]'),
+    (1, 1, 'MI', 3, 'Mexicantown', '[]'),
+    (2, 0, 'MC', 4, 'Arcadia Planitia', '[]')
 ;
 
 INSERT INTO simple_primary_key VALUES (1, 'hello');

tests/test_api.py

@@ -1,3 +1,4 @@
+from datasette.utils import detect_json1
 from .fixtures import ( # noqa
     app_client,
     app_client_no_files,
@@ -115,7 +116,7 @@ def test_database_page(app_client):
         'hidden': False,
         'primary_keys': ['id'],
     }, {
-        'columns': ['pk', 'planet_int', 'on_earth', 'state', 'city_id', 'neighborhood'],
+        'columns': ['pk', 'planet_int', 'on_earth', 'state', 'city_id', 'neighborhood', 'tags'],
         'name': 'facetable',
         'count': 15,
         'foreign_keys': {
@@ -882,6 +883,18 @@ def test_table_filter_queries(app_client, path, expected_rows):
     assert expected_rows == response.json['rows']
 
 
+@pytest.mark.skipif(
+    not detect_json1(),
+    reason="Requires the SQLite json1 module"
+)
+def test_table_filter_json_arraycontains(app_client):
+    response = app_client.get("/fixtures/facetable.json?tags__arraycontains=tag1")
+    assert [
+        [1, 1, 1, 'CA', 1, 'Mission', '["tag1", "tag2"]'],
+        [2, 1, 1, 'CA', 1, 'Dogpatch', '["tag1", "tag3"]']
+    ] == response.json['rows']
+
+
 def test_max_returned_rows(app_client):
     response = app_client.get(
         '/fixtures.json?sql=select+content+from+no_primary_key'
@@ -1244,7 +1257,8 @@ def test_expand_labels(app_client):
                 "value": 1,
                 "label": "San Francisco"
             },
-            "neighborhood": "Dogpatch"
+            "neighborhood": "Dogpatch",
+            "tags": '["tag1", "tag3"]'
         },
         "13": {
             "pk": 13,
@@ -1255,7 +1269,8 @@ def test_expand_labels(app_client):
                 "value": 3,
                 "label": "Detroit"
             },
-            "neighborhood": "Corktown"
+            "neighborhood": "Corktown",
+            "tags": '[]',
         }
     } == response.json
 

tests/test_csv.py

@@ -17,22 +17,22 @@ world
 '''.replace('\n', '\r\n')
 
 EXPECTED_TABLE_WITH_LABELS_CSV = '''
-pk,planet_int,on_earth,state,city_id,city_id_label,neighborhood
-1,1,1,CA,1,San Francisco,Mission
-2,1,1,CA,1,San Francisco,Dogpatch
-3,1,1,CA,1,San Francisco,SOMA
-4,1,1,CA,1,San Francisco,Tenderloin
-5,1,1,CA,1,San Francisco,Bernal Heights
-6,1,1,CA,1,San Francisco,Hayes Valley
-7,1,1,CA,2,Los Angeles,Hollywood
-8,1,1,CA,2,Los Angeles,Downtown
-9,1,1,CA,2,Los Angeles,Los Feliz
-10,1,1,CA,2,Los Angeles,Koreatown
-11,1,1,MI,3,Detroit,Downtown
-12,1,1,MI,3,Detroit,Greektown
-13,1,1,MI,3,Detroit,Corktown
-14,1,1,MI,3,Detroit,Mexicantown
-15,2,0,MC,4,Memnonia,Arcadia Planitia
+pk,planet_int,on_earth,state,city_id,city_id_label,neighborhood,tags
+1,1,1,CA,1,San Francisco,Mission,"[""tag1"", ""tag2""]"
+2,1,1,CA,1,San Francisco,Dogpatch,"[""tag1"", ""tag3""]"
+3,1,1,CA,1,San Francisco,SOMA,[]
+4,1,1,CA,1,San Francisco,Tenderloin,[]
+5,1,1,CA,1,San Francisco,Bernal Heights,[]
+6,1,1,CA,1,San Francisco,Hayes Valley,[]
+7,1,1,CA,2,Los Angeles,Hollywood,[]
+8,1,1,CA,2,Los Angeles,Downtown,[]
+9,1,1,CA,2,Los Angeles,Los Feliz,[]
+10,1,1,CA,2,Los Angeles,Koreatown,[]
+11,1,1,MI,3,Detroit,Downtown,[]
+12,1,1,MI,3,Detroit,Greektown,[]
+13,1,1,MI,3,Detroit,Corktown,[]
+14,1,1,MI,3,Detroit,Mexicantown,[]
+15,2,0,MC,4,Memnonia,Arcadia Planitia,[]
 '''.lstrip().replace('\n', '\r\n')
 
 

tests/test_utils.py

@@ -187,7 +187,7 @@ def test_custom_json_encoder(obj, expected):
 ])
 def test_build_where(args, expected_where, expected_params):
     f = utils.Filters(sorted(args.items()))
-    sql_bits, actual_params = f.build_where_clauses()
+    sql_bits, actual_params = f.build_where_clauses("table")
     assert expected_where == sql_bits
     assert {
         'p{}'.format(i): param