Edit SQL button on canned queries, closes #1019

datasette/static/app.css

@@ -447,3 +447,9 @@ svg.dropdown-menu-icon {
     border-right: 5px solid transparent;
     border-bottom: 5px solid #666;
 }
+
+.canned-query-edit-sql {
+    padding-left: 0.5em;
+    position: relative;
+    top: 1px;
+}

datasette/templates/query.html

@@ -54,6 +54,7 @@
         <button id="sql-format" type="button" hidden>Format SQL</button>
         {% if canned_write %}<input type="hidden" name="csrftoken" value="{{ csrftoken() }}">{% endif %}
         <input type="submit" value="Run SQL">
+        {% if canned_query and edit_sql_url %}<a href="{{ edit_sql_url }}" class="canned-query-edit-sql">Edit SQL</a>{% endif %}
     </p>
 </form>
 

datasette/views/database.py

@@ -2,7 +2,7 @@ import os
 import itertools
 import jinja2
 import json
-from urllib.parse import parse_qsl
+from urllib.parse import parse_qsl, urlencode
 
 from datasette.utils import (
     check_visibility,
@@ -11,6 +11,7 @@ from datasette.utils import (
     is_url,
     path_with_added_args,
     path_with_removed_args,
+    InvalidSql,
 )
 from datasette.utils.asgi import AsgiFileDownload, Response, Forbidden
 from datasette.plugins import pm
@@ -301,6 +302,10 @@ class QueryView(DataView):
                 ),
             )
 
+        allow_execute_sql = await self.ds.permission_allowed(
+            request.actor, "execute-sql", database, default=True
+        )
+
         async def extra_template():
             display_rows = []
             for row in results.rows:
@@ -329,12 +334,38 @@ class QueryView(DataView):
                             )
                     display_row.append(display_value)
                 display_rows.append(display_row)
+
+            # Show 'Edit SQL' button only if:
+            # - User is allowed to execute SQL
+            # - SQL is an approved SELECT statement
+            # - No magic parameters, so no :_ in the SQL string
+            edit_sql_url = None
+            is_validated_sql = False
+            try:
+                validate_sql_select(sql)
+                is_validated_sql = True
+            except InvalidSql:
+                pass
+            if allow_execute_sql and is_validated_sql and ":_" not in sql:
+                edit_sql_url = (
+                    self.database_url(database)
+                    + "?"
+                    + urlencode(
+                        {
+                            **{
+                                "sql": sql,
+                            },
+                            **named_parameter_values,
+                        }
+                    )
+                )
             return {
                 "display_rows": display_rows,
                 "custom_sql": True,
                 "named_parameter_values": named_parameter_values,
                 "editable": editable,
                 "canned_query": canned_query,
+                "edit_sql_url": edit_sql_url,
                 "metadata": metadata,
                 "config": self.ds.config_dict(),
                 "request": request,
@@ -352,9 +383,7 @@ class QueryView(DataView):
                 "columns": columns,
                 "query": {"sql": sql, "params": params},
                 "private": private,
-                "allow_execute_sql": await self.ds.permission_allowed(
-                    request.actor, "execute-sql", database, default=True
-                ),
+                "allow_execute_sql": allow_execute_sql,
             },
             extra_template,
             templates,

tests/test_html.py

@@ -1403,3 +1403,48 @@ def test_base_url_config(base_url, path):
                     "href_or_src": href,
                     "element_parent": str(el.parent),
                 }
+
+
+@pytest.mark.parametrize(
+    "path,expected",
+    [
+        (
+            "/fixtures/neighborhood_search",
+            "/fixtures?sql=%0Aselect+neighborhood%2C+facet_cities.name%2C+state%0Afrom+facetable%0A++++join+facet_cities%0A++++++++on+facetable.city_id+%3D+facet_cities.id%0Awhere+neighborhood+like+%27%25%27+%7C%7C+%3Atext+%7C%7C+%27%25%27%0Aorder+by+neighborhood%3B%0A&text=",
+        ),
+        (
+            "/fixtures/neighborhood_search?text=ber",
+            "/fixtures?sql=%0Aselect+neighborhood%2C+facet_cities.name%2C+state%0Afrom+facetable%0A++++join+facet_cities%0A++++++++on+facetable.city_id+%3D+facet_cities.id%0Awhere+neighborhood+like+%27%25%27+%7C%7C+%3Atext+%7C%7C+%27%25%27%0Aorder+by+neighborhood%3B%0A&text=ber",
+        ),
+        ("/fixtures/pragma_cache_size", None),
+        (
+            "/fixtures/𝐜𝐢𝐭𝐢𝐞𝐬",
+            "/fixtures?sql=select+id%2C+name+from+facet_cities+order+by+id+limit+1%3B",
+        ),
+        ("/fixtures/magic_parameters", None),
+    ],
+)
+def test_edit_sql_link_on_canned_queries(app_client, path, expected):
+    response = app_client.get(path)
+    expected_link = '<a href="{}" class="canned-query-edit-sql">Edit SQL</a>'.format(
+        expected
+    )
+    if expected:
+        assert expected_link in response.text
+    else:
+        assert "Edit SQL" not in response.text
+
+
+@pytest.mark.parametrize("permission_allowed", [True, False])
+def test_edit_sql_link_not_shown_if_user_lacks_permission(permission_allowed):
+    with make_app_client(
+        metadata={
+            "allow_sql": None if permission_allowed else {"id": "not-you"},
+            "databases": {"fixtures": {"queries": {"simple": "select 1 + 1"}}},
+        }
+    ) as client:
+        response = client.get("/fixtures/simple")
+        if permission_allowed:
+            assert "Edit SQL" in response.text
+        else:
+            assert "Edit SQL" not in response.text