Moved expand_foreign_keys method to Database

Refs #620

Also fixed a few places that were calling ds.execute() instead of
db.execute()

datasette/app.py

@@ -352,43 +352,6 @@ class Datasette:
             log_sql_errors=log_sql_errors,
         )
 
-    async def expand_foreign_keys(self, database, table, column, values):
-        "Returns dict mapping (column, value) -> label"
-        labeled_fks = {}
-        db = self.databases[database]
-        foreign_keys = await db.foreign_keys_for_table(table)
-        # Find the foreign_key for this column
-        try:
-            fk = [
-                foreign_key
-                for foreign_key in foreign_keys
-                if foreign_key["column"] == column
-            ][0]
-        except IndexError:
-            return {}
-        label_column = await db.label_column_for_table(fk["other_table"])
-        if not label_column:
-            return {(fk["column"], value): str(value) for value in values}
-        labeled_fks = {}
-        sql = """
-            select {other_column}, {label_column}
-            from {other_table}
-            where {other_column} in ({placeholders})
-        """.format(
-            other_column=escape_sqlite(fk["other_column"]),
-            label_column=escape_sqlite(label_column),
-            other_table=escape_sqlite(fk["other_table"]),
-            placeholders=", ".join(["?"] * len(set(values))),
-        )
-        try:
-            results = await self.execute(database, sql, list(set(values)))
-        except QueryInterrupted:
-            pass
-        else:
-            for id, value in results:
-                labeled_fks[(fk["column"], id)] = value
-        return labeled_fks
-
     def absolute_url(self, request, path):
         url = urllib.parse.urljoin(request.url, path)
         if url.startswith("http://") and self.config("force_https_urls"):

datasette/database.py

@@ -10,6 +10,7 @@ from .utils import (
     detect_fts,
     detect_primary_keys,
     detect_spatialite,
+    escape_sqlite,
     get_all_foreign_keys,
     get_outbound_foreign_keys,
     sqlite_timelimit,
@@ -217,6 +218,42 @@ class Database:
             lambda conn: get_outbound_foreign_keys(conn, table)
         )
 
+    async def expand_foreign_keys(self, table, column, values, fks=None):
+        "Returns dict mapping (column, value) -> label"
+        labeled_fks = {}
+        foreign_keys = fks or await self.foreign_keys_for_table(table)
+        # Find the foreign_key for this column
+        try:
+            fk = [
+                foreign_key
+                for foreign_key in foreign_keys
+                if foreign_key["column"] == column
+            ][0]
+        except IndexError:
+            return {}
+        label_column = await self.label_column_for_table(fk["other_table"])
+        if not label_column:
+            return {(fk["column"], value): str(value) for value in values}
+        labeled_fks = {}
+        sql = """
+            select {other_column}, {label_column}
+            from {other_table}
+            where {other_column} in ({placeholders})
+        """.format(
+            other_column=escape_sqlite(fk["other_column"]),
+            label_column=escape_sqlite(label_column),
+            other_table=escape_sqlite(fk["other_table"]),
+            placeholders=", ".join(["?"] * len(set(values))),
+        )
+        try:
+            results = await self.execute(sql, list(set(values)))
+        except QueryInterrupted:
+            pass
+        else:
+            for id, value in results:
+                labeled_fks[(fk["column"], id)] = value
+        return labeled_fks
+
     async def hidden_table_names(self):
         # Mark tables 'hidden' if they relate to FTS virtual tables
         hidden_tables = [

datasette/facets.py

@@ -139,6 +139,7 @@ class ColumnFacet(Facet):
         facet_size = self.ds.config("default_facet_size")
         suggested_facets = []
         already_enabled = [c["config"]["simple"] for c in self.get_configs()]
+        database = self.ds.databases[self.database]
         for column in columns:
             if column in already_enabled:
                 continue
@@ -152,8 +153,7 @@ class ColumnFacet(Facet):
             )
             distinct_values = None
             try:
-                distinct_values = await self.ds.execute(
-                    self.database,
+                distinct_values = await database.execute(
                     suggested_facet_sql,
                     self.params,
                     truncate=False,
@@ -182,6 +182,7 @@ class ColumnFacet(Facet):
     async def facet_results(self):
         facet_results = {}
         facets_timed_out = []
+        database = self.ds.databases[self.database]
 
         qs_pairs = self.get_querystring_pairs()
 
@@ -200,8 +201,7 @@ class ColumnFacet(Facet):
                 col=escape_sqlite(column), sql=self.sql, limit=facet_size + 1
             )
             try:
-                facet_rows_results = await self.ds.execute(
-                    self.database,
+                facet_rows_results = await database.execute(
                     facet_sql,
                     self.params,
                     truncate=False,
@@ -222,8 +222,8 @@ class ColumnFacet(Facet):
                 if self.table:
                     # Attempt to expand foreign keys into labels
                     values = [row["value"] for row in facet_rows]
-                    expanded = await self.ds.expand_foreign_keys(
-                        self.database, self.table, column, values
+                    expanded = await database.expand_foreign_keys(
+                        self.table, column, values
                     )
                 else:
                     expanded = {}

datasette/views/table.py

@@ -74,17 +74,42 @@ class RowTableShared(DataView):
             sortable_columns.add("rowid")
         return sortable_columns
 
-    async def expandable_columns(self, database, table):
+    async def foreign_keys_for_table(self, request, database, table):
+        db = self.ds.databases[database]
+        fks = await db.foreign_keys_for_table(table)
+        # Handle ?_fk.article_id=articles.id querystring arguments
+        for key, value in request.args.items():
+            if key.startswith("_fk."):
+                value = value[0]
+                column = key.split("_fk.", 1)[1]
+                other_table, other_column = value.split(".", 1)
+                # {'other_table': '...', 'column': '...', 'other_column': 'id'}
+                expandable_fk = {
+                    "other_table": other_table,
+                    "column": column,
+                    "other_column": other_column,
+                }
+                fks.append(expandable_fk)
+        return fks
+
+    async def expandable_columns(self, request, database, table):
         # Returns list of (fk_dict, label_column-or-None) pairs for that table
         expandables = []
         db = self.ds.databases[database]
-        for fk in await db.foreign_keys_for_table(table):
+        for fk in await self.foreign_keys_for_table(request, database, table):
             label_column = await db.label_column_for_table(fk["other_table"])
             expandables.append((fk, label_column))
         return expandables
 
     async def display_columns_and_rows(
-        self, database, table, description, rows, link_column=False, truncate_cells=0
+        self,
+        request,
+        database,
+        table,
+        description,
+        rows,
+        link_column=False,
+        truncate_cells=0,
     ):
         "Returns columns, rows for specified table - including fancy foreign key treatment"
         db = self.ds.databases[database]
@@ -96,7 +121,7 @@ class RowTableShared(DataView):
         pks = await db.primary_keys(table)
         column_to_foreign_key_table = {
             fk["column"]: fk["other_table"]
-            for fk in await db.foreign_keys_for_table(table)
+            for fk in await self.foreign_keys_for_table(request, database, table)
         }
 
         cell_rows = []
@@ -533,17 +558,13 @@ class TableView(RowTableShared):
         if request.raw_args.get("_timelimit"):
             extra_args["custom_time_limit"] = int(request.raw_args["_timelimit"])
 
-        results = await self.ds.execute(
-            database, sql, params, truncate=True, **extra_args
-        )
+        results = await db.execute(sql, params, truncate=True, **extra_args)
 
         # Number of filtered rows in whole set:
         filtered_table_rows_count = None
         if count_sql:
             try:
-                count_rows = list(
-                    await self.ds.execute(database, count_sql, from_sql_params)
-                )
+                count_rows = list(await db.execute(count_sql, from_sql_params))
                 filtered_table_rows_count = count_rows[0][0]
             except QueryInterrupted:
                 pass
@@ -593,7 +614,7 @@ class TableView(RowTableShared):
 
         # Expand labeled columns if requested
         expanded_columns = []
-        expandable_columns = await self.expandable_columns(database, table)
+        expandable_columns = await self.expandable_columns(request, database, table)
         columns_to_expand = None
         try:
             all_labels = value_as_boolean(special_args.get("_labels", ""))
@@ -618,7 +639,9 @@ class TableView(RowTableShared):
                 values = [row[column_index] for row in rows]
                 # Expand them
                 expanded_labels.update(
-                    await self.ds.expand_foreign_keys(database, table, column, values)
+                    await db.expand_foreign_keys(
+                        table, column, values, fks=[p[0] for p in expandable_columns],
+                    )
                 )
             if expanded_labels:
                 # Rewrite the rows
@@ -693,6 +716,7 @@ class TableView(RowTableShared):
 
         async def extra_template():
             display_columns, display_rows = await self.display_columns_and_rows(
+                request,
                 database,
                 table,
                 results.description,
@@ -799,7 +823,7 @@ class RowView(RowTableShared):
         params = {}
         for i, pk_value in enumerate(pk_values):
             params["p{}".format(i)] = pk_value
-        results = await self.ds.execute(database, sql, params, truncate=True)
+        results = await db.execute(sql, params, truncate=True)
         columns = [r[0] for r in results.description]
         rows = list(results.rows)
         if not rows:
@@ -807,6 +831,7 @@ class RowView(RowTableShared):
 
         async def template_data():
             display_columns, display_rows = await self.display_columns_and_rows(
+                request,
                 database,
                 table,
                 results.description,
@@ -880,7 +905,7 @@ class RowView(RowTableShared):
             ]
         )
         try:
-            rows = list(await self.ds.execute(database, sql, {"id": pk_values[0]}))
+            rows = list(await db.execute(sql, {"id": pk_values[0]}))
         except sqlite3.OperationalError:
             # Almost certainly hit the timeout
             return []