sqlite-utils --attach option, closes #236

tests/test_cli.py

@@ -1855,3 +1855,25 @@ def test_csv_import_no_headers(tmpdir, args):
         {"untitled_1": "Cleo", "untitled_2": "Dog", "untitled_3": "5"},
         {"untitled_1": "Tracy", "untitled_2": "Spider", "untitled_3": "7"},
     ]
+
+
+def test_attach(tmpdir):
+    foo_path = str(tmpdir / "foo.db")
+    bar_path = str(tmpdir / "bar.db")
+    db = Database(foo_path)
+    with db.conn:
+        db["foo"].insert({"id": 1, "text": "foo"})
+    db2 = Database(bar_path)
+    with db2.conn:
+        db2["bar"].insert({"id": 1, "text": "bar"})
+    db.attach("bar", bar_path)
+    sql = "select * from foo union all select * from bar.bar"
+    result = CliRunner().invoke(
+        cli.cli,
+        [foo_path, "--attach", "bar", bar_path, sql],
+        catch_exceptions=False,
+    )
+    assert json.loads(result.output) == [
+        {"id": 1, "text": "foo"},
+        {"id": 1, "text": "bar"},
+    ]