Compound primary key support for /db/-/create - closes #1911

Needed for tests in #1864

datasette/views/database.py

@@ -701,7 +701,7 @@ async def _table_columns(datasette, database_name):
 class TableCreateView(BaseView):
     name = "table-create"
 
-    _valid_keys = {"table", "rows", "row", "columns", "pk"}
+    _valid_keys = {"table", "rows", "row", "columns", "pk", "pks"}
     _supported_column_types = {
         "text",
         "integer",
@@ -785,18 +785,28 @@ class TableCreateView(BaseView):
                     return _error(["rows must be a list of objects"])
 
         pk = data.get("pk")
+        pks = data.get("pks")
+
+        if pk and pks:
+            return _error(["Cannot specify both pk and pks"])
         if pk:
             if not isinstance(pk, str):
                 return _error(["pk must be a string"])
+        if pks:
+            if not isinstance(pks, list):
+                return _error(["pks must be a list"])
+            for pk in pks:
+                if not isinstance(pk, str):
+                    return _error(["pks must be a list of strings"])
 
         def create_table(conn):
             table = sqlite_utils.Database(conn)[table_name]
             if rows:
-                table.insert_all(rows, pk=pk)
+                table.insert_all(rows, pk=pks or pk)
             else:
                 table.create(
                     {c["name"]: c["type"] for c in columns},
-                    pk=pk,
+                    pk=pks or pk,
                 )
             return table.schema
 

docs/json_api.rst

@@ -666,6 +666,8 @@ The JSON here describes the table that will be created:
 
     If you set this to ``id`` without including an ``id`` column in the list of ``columns``, Datasette will create an integer ID column for you.
 
+*   ``pks`` can be used instead of ``pk`` to create a compound primary key. It should be a JSON list of column names to use in that primary key.
+
 If the table is successfully created this will return a ``201`` status code and the following response:
 
 .. code-block:: json

tests/test_api_write.py

@@ -643,6 +643,27 @@ async def test_drop_table(ds_write, scenario):
                 "row_count": 1,
             },
         ),
+        # Create table with compound primary key
+        (
+            {
+                "table": "five",
+                "row": {"type": "article", "key": 123, "title": "Article 1"},
+                "pks": ["type", "key"],
+            },
+            201,
+            {
+                "ok": True,
+                "database": "data",
+                "table": "five",
+                "table_url": "http://localhost/data/five",
+                "table_api_url": "http://localhost/data/five.json",
+                "schema": (
+                    "CREATE TABLE [five] (\n   [type] TEXT,\n   [key] INTEGER,\n"
+                    "   [title] TEXT,\n   PRIMARY KEY ([type], [key])\n)"
+                ),
+                "row_count": 1,
+            },
+        ),
         # Error: Table is required
         (
             {
@@ -799,6 +820,39 @@ async def test_drop_table(ds_write, scenario):
                 "errors": ["pk must be a string"],
             },
         ),
+        # Error: Cannot specify both pk and pks
+        (
+            {
+                "table": "bad",
+                "row": {"id": 1, "name": "Row 1"},
+                "pk": "id",
+                "pks": ["id", "name"],
+            },
+            400,
+            {
+                "ok": False,
+                "errors": ["Cannot specify both pk and pks"],
+            },
+        ),
+        # Error: pks must be a list
+        (
+            {
+                "table": "bad",
+                "row": {"id": 1, "name": "Row 1"},
+                "pks": "id",
+            },
+            400,
+            {
+                "ok": False,
+                "errors": ["pks must be a list"],
+            },
+        ),
+        # Error: pks must be a list of strings
+        (
+            {"table": "bad", "row": {"id": 1, "name": "Row 1"}, "pks": [1, 2]},
+            400,
+            {"ok": False, "errors": ["pks must be a list of strings"]},
+        ),
     ),
 )
 async def test_create_table(ds_write, input, expected_status, expected_response):