recursive_triggers=on by default, closes #152

Refs #149

docs/python-api.rst

@@ -37,6 +37,12 @@ If you want to create an in-memory database, you can do so like this:
 
     db = Database(memory=True)
 
+Connections use ``PRAGMA recursive_triggers=on`` by default. If you don't want to use `recursive triggers <https://www.sqlite.org/pragma.html#pragma_recursive_triggers>`__ you can turn them off using:
+
+.. code-block:: python
+
+    db = Database(memory=True, recursive_triggers=False)
+
 Tables are accessed using the indexing operator, like so:
 
 .. code-block:: python

sqlite_utils/db.py

@@ -103,7 +103,13 @@ class PrimaryKeyRequired(Exception):
 
 
 class Database:
-    def __init__(self, filename_or_conn=None, memory=False, recreate=False):
+    def __init__(
+        self,
+        filename_or_conn=None,
+        memory=False,
+        recreate=False,
+        recursive_triggers=True,
+    ):
         assert (filename_or_conn is not None and not memory) or (
             filename_or_conn is None and memory
         ), "Either specify a filename_or_conn or pass memory=True"
@@ -116,6 +122,8 @@ def __init__(self, filename_or_conn=None, memory=False, recreate=False):
         else:
             assert not recreate, "recreate cannot be used with connections, only paths"
             self.conn = filename_or_conn
+        if recursive_triggers:
+            self.conn.execute("PRAGMA recursive_triggers=on;")
 
     def __getitem__(self, table_name):
         return self.table(table_name)

tests/test_constructor.py

@@ -0,0 +1,12 @@
+from sqlite_utils import Database
+import pytest
+
+
+def test_recursive_triggers():
+    db = Database(memory=True)
+    assert db.conn.execute("PRAGMA recursive_triggers").fetchone()[0]
+
+
+def test_recursive_triggers_off():
+    db = Database(memory=True, recursive_triggers=False)
+    assert not db.conn.execute("PRAGMA recursive_triggers").fetchone()[0]