From 0e60f3c80cd6df5c177d8405afc54d014addebd0 Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Wed, 13 Apr 2022 15:39:48 -0700
Subject: [PATCH] Better error message if table has no columns, closes #424

---
 sqlite_utils/db.py   | 1 +
 tests/test_create.py | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/sqlite_utils/db.py b/sqlite_utils/db.py
index dcbc2b6..82156b9 100644
--- a/sqlite_utils/db.py
+++ b/sqlite_utils/db.py
@@ -768,6 +768,7 @@ class Database:
         # Soundness check not_null, and defaults if provided
         not_null = not_null or set()
         defaults = defaults or {}
+        assert columns, "Tables must have at least one column"
         assert all(
             n in columns for n in not_null
         ), "not_null set {} includes items not in columns {}".format(
diff --git a/tests/test_create.py b/tests/test_create.py
index c3871e1..60181de 100644
--- a/tests/test_create.py
+++ b/tests/test_create.py
@@ -1149,3 +1149,9 @@ def test_create_if_not_exists(fresh_db):
         fresh_db["t"].create({"id": int})
     # This should not
     fresh_db["t"].create({"id": int}, if_not_exists=True)
+
+
+def test_create_if_no_columns(fresh_db):
+    with pytest.raises(AssertionError) as error:
+        fresh_db["t"].create({})
+    assert error.value.args[0] == "Tables must have at least one column"