Unify create and alter table modal controls

Share default value controls between the create and alter table dialogs and expose create-table default expressions to the frontend.

Add create-table not-null/default handling and align the shared foreign key picker behavior across both dialogs.

datasette/static/app.css

@@ -1883,12 +1883,14 @@ select.table-create-input {
 }
 
 .table-create-foreign-key-target option,
-.table-create-custom-column-type option {
+.table-create-custom-column-type option,
+.table-create-default-expr option {
     color: var(--ink);
 }
 
 .table-create-foreign-key-target option[value=""],
-.table-create-custom-column-type option[value=""] {
+.table-create-custom-column-type option[value=""],
+.table-create-default-expr option[value=""] {
     color: var(--muted);
 }
 
@@ -1978,11 +1980,44 @@ select.table-create-input {
     white-space: normal;
 }
 
+.table-create-not-null,
 .table-create-primary-key,
-.table-create-foreign-key-field {
+.table-create-foreign-key-field,
+.table-create-default-options {
     grid-column: 1 / -1;
 }
 
+.table-create-default-options,
+.table-alter-default-options {
+    border: 1px solid var(--rule);
+    border-radius: 5px;
+    background: #fff;
+    color: var(--ink);
+    min-width: 0;
+}
+
+.table-create-default-options > summary,
+.table-alter-default-options > summary {
+    cursor: pointer;
+    color: var(--accent);
+    font-size: 0.85rem;
+    padding: 8px 10px;
+}
+
+.table-create-default-options > summary:focus,
+.table-alter-default-options > summary:focus {
+    outline: 3px solid rgba(26, 86, 219, 0.12);
+    outline-offset: 1px;
+}
+
+.table-create-default-grid,
+.table-alter-default-grid {
+    display: grid;
+    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
+    gap: 12px 16px;
+    padding: 0 10px 10px;
+}
+
 .table-create-detail-check input {
     flex: 0 0 auto;
     margin: 0.15rem 0 0;
@@ -2221,6 +2256,7 @@ dialog.table-alter-dialog::backdrop {
     overflow-y: auto;
 }
 
+
 .table-alter-fields[hidden],
 .table-alter-dialog .modal-footer [hidden] {
     display: none;
@@ -2358,12 +2394,14 @@ select.table-alter-input {
 }
 
 .table-alter-default-expr option,
-.table-alter-custom-column-type option {
+.table-alter-custom-column-type option,
+.table-alter-foreign-key-target option {
     color: var(--ink);
 }
 
 .table-alter-default-expr option[value=""],
-.table-alter-custom-column-type option[value=""] {
+.table-alter-custom-column-type option[value=""],
+.table-alter-foreign-key-target option[value=""] {
     color: var(--muted);
 }
 
@@ -2410,7 +2448,9 @@ select.table-alter-input {
 }
 
 .table-alter-not-null,
-.table-alter-primary-key {
+.table-alter-primary-key,
+.table-alter-foreign-key-field,
+.table-alter-default-options {
     grid-column: 1 / -1;
 }
 
@@ -2657,6 +2697,10 @@ select.table-alter-input {
         grid-template-columns: 1fr;
     }
 
+    .table-alter-default-grid {
+        grid-template-columns: 1fr;
+    }
+
     .table-alter-dialog .modal-footer {
         padding-left: 18px;
         padding-right: 18px;
@@ -2878,6 +2922,10 @@ select.table-alter-input {
         grid-template-columns: 1fr;
     }
 
+    .table-create-default-grid {
+        grid-template-columns: 1fr;
+    }
+
     .table-create-dialog .modal-footer {
         padding-left: 18px;
         padding-right: 18px;

datasette/views/table_create_alter.py

@@ -266,6 +266,7 @@ async def _create_table_ui_context(
         ),
         "databaseName": database_name,
         "columnTypes": CREATE_TABLE_COLUMN_TYPES,
+        "defaultExpressions": list(DEFAULT_EXPR_SQL),
     }
     can_set_column_type = await datasette.allowed(
         action="set-column-type",

tests/test_playwright.py

@@ -295,6 +295,10 @@ def test_create_table_flow(page, datasette_server):
         placeholder_select.locator("option:checked").inner_text() == "- custom type -"
     )
     assert "table-create-input-placeholder" in placeholder_select.get_attribute("class")
+    assert (
+        dialog.locator(".table-create-column-name").nth(0).get_attribute("placeholder")
+        == "column name"
+    )
     assert dialog.locator(".table-create-column-main").first.evaluate("""node => {
             const inputHeight = node.querySelector(
                 ".table-create-column-name"
@@ -306,6 +310,22 @@ def test_create_table_flow(page, datasette_server):
         }""")
     dialog.locator('input[name="table"]').fill("playwright_created")
     dialog.locator(".table-create-column-name").nth(1).fill("title")
+    dialog.locator(".table-create-more-options").nth(1).click()
+    dialog.locator(".table-create-not-null-input").nth(1).check()
+    title_defaults = dialog.locator(".table-create-default-options").nth(1)
+    assert title_defaults.locator("summary").inner_text() == "Set a default value"
+    title_defaults.locator("summary").click()
+    assert "or default to a specific value" in title_defaults.inner_text()
+    title_default_expr = title_defaults.locator(".table-create-default-expr")
+    title_default_input = title_defaults.locator(".table-create-default")
+    assert (
+        "Current timestamp in UTC, e.g. 2026-05-01 13:34:00"
+        in title_default_expr.locator("option").nth(1).inner_text()
+    )
+    title_default_expr.select_option("current_timestamp")
+    assert title_default_input.is_enabled()
+    title_default_input.fill("Untitled")
+    assert title_default_expr.input_value() == ""
     dialog.locator(".table-create-add-column").click()
     dialog.locator(".table-create-column-name").nth(2).fill("score")
     dialog.locator(".table-create-column-type").nth(2).select_option("integer")
@@ -337,6 +357,63 @@ def test_create_table_flow(page, datasette_server):
     assert data["column_types"] == {
         "metadata": {"type": "json", "config": None},
     }
+    schema_response = httpx.get(
+        f"{datasette_server}data/-/query.json",
+        params={
+            "sql": (
+                "select sql from sqlite_master where type = 'table' "
+                "and name = 'playwright_created'"
+            )
+        },
+    )
+    schema_response.raise_for_status()
+    schema = schema_response.json()["rows"][0]["sql"]
+    assert "title" in schema
+    assert "NOT NULL DEFAULT 'Untitled'" in schema
+
+
+@pytest.mark.playwright
+def test_create_table_foreign_key_selection_updates_column_type(page, datasette_server):
+    page.goto(f"{datasette_server}data")
+    page.locator("details.actions-menu-links summary").click()
+    page.locator('button[data-database-action="create-table"]').click()
+
+    dialog = page.locator("#table-create-dialog")
+    dialog.wait_for()
+    dialog.locator(".table-create-more-options").nth(1).click()
+
+    column_name = dialog.locator(".table-create-column-name").nth(1)
+    type_select = dialog.locator(".table-create-column-type").nth(1)
+    foreign_key_select = dialog.locator(".table-create-foreign-key-target").nth(1)
+    assert column_name.input_value() == ""
+    assert type_select.input_value() == "text"
+
+    foreign_key_select.select_option("projects\u001fid")
+    assert column_name.input_value() == "projects_id"
+    assert type_select.input_value() == "integer"
+    assert foreign_key_select.input_value() == "projects\u001fid"
+
+
+@pytest.mark.playwright
+def test_alter_table_foreign_key_selection_updates_blank_column(page, datasette_server):
+    page.goto(f"{datasette_server}data/projects")
+    page.locator("details.actions-menu-links summary").click()
+    page.locator('button[data-table-action="alter-table"]').click()
+
+    dialog = page.locator("#table-alter-dialog")
+    dialog.wait_for()
+    dialog.locator(".table-alter-add-column").click()
+
+    column_name = dialog.locator(".table-alter-column-name").last
+    type_select = dialog.locator(".table-alter-column-type").last
+    foreign_key_select = dialog.locator(".table-alter-foreign-key-target").last
+    assert column_name.input_value() == ""
+    assert type_select.input_value() == "text"
+
+    foreign_key_select.select_option("projects\u001fid")
+    assert column_name.input_value() == "projects_id"
+    assert type_select.input_value() == "integer"
+    assert foreign_key_select.input_value() == "projects\u001fid"
 
 
 @pytest.mark.playwright
@@ -349,6 +426,10 @@ def test_alter_table_flow(page, datasette_server):
     dialog.wait_for()
     assert dialog.locator(".modal-title").inner_text() == "Alter table projects"
     assert dialog.locator(".table-alter-save").is_disabled()
+    assert (
+        dialog.locator(".table-alter-column-name").first.get_attribute("placeholder")
+        == "column name"
+    )
     assert dialog.locator(".table-alter-column-main").first.evaluate("""node => {
             const inputHeight = node.querySelector(
                 ".table-alter-column-name"
@@ -377,15 +458,29 @@ def test_alter_table_flow(page, datasette_server):
     )
     assert "Not null" in expanded_options_text
     assert "This value cannot be left unset" in expanded_options_text
-    assert "Default value" in expanded_options_text
-    assert "or default to a specific time" in expanded_options_text
+    assert "Set a default value" in expanded_options_text
     assert "Primary key" in expanded_options_text
     assert "This ID uniquely identifies the record" in expanded_options_text
+    assert "Foreign key" in expanded_options_text
+    first_defaults = dialog.locator(".table-alter-default-options").first
+    first_defaults.locator("summary").click()
+    assert "or default to a specific value" in first_defaults.inner_text()
+    first_default_expr = first_defaults.locator(".table-alter-default-expr")
+    first_default_input = first_defaults.locator(".table-alter-default")
+    assert (
+        "Current timestamp in UTC, e.g. 2026-05-01 13:34:00"
+        in first_default_expr.locator("option").nth(1).inner_text()
+    )
+    first_default_expr.select_option("current_timestamp")
+    assert first_default_input.is_enabled()
+    first_default_input.fill("manual")
+    assert first_default_expr.input_value() == ""
 
     dialog.locator(".table-alter-add-column").click()
     assert dialog.locator(".table-alter-save").is_enabled()
     dialog.locator(".table-alter-column-name").last.fill("status")
     dialog.locator(".table-alter-column-type").last.select_option("text")
+    dialog.locator(".table-alter-default-options").last.locator("summary").click()
     dialog.locator(".table-alter-default").last.fill("planned")
     dialog.locator(".table-alter-save").click()
     review = dialog.locator(".table-alter-review")

tests/test_table_html.py

@@ -997,6 +997,11 @@ async def test_database_create_table_action_button_and_data():
                 "foreignKeyTargetsPath": "/data/-/foreign-key-targets",
                 "databaseName": "data",
                 "columnTypes": ["text", "integer", "float", "blob"],
+                "defaultExpressions": [
+                    "current_timestamp",
+                    "current_date",
+                    "current_time",
+                ],
             },
         }
         assert "customColumnTypes" not in database_data_from_soup(soup)["createTable"]