rework of select tests

tests/test_sqlite.py

@@ -15,16 +15,21 @@ from cbutil.util import time_conversion
 def test_select():
     assert select_stmt().strip() == "SELECT *"
     assert select_stmt("test").strip() == "SELECT test"
-    with pytest.raises(ValueError):
-        select_stmt("")
-    with pytest.raises(ValueError):
-        select_stmt("     ")
 
 
-def test_from():
-    assert from_stmt("table").strip() == "FROM table"
+@pytest.mark.parametrize("select", ["", "  "])
+def test_invalid_select(select):
     with pytest.raises(ValueError):
-        from_stmt("")
+        select_stmt(select)
+
+
+@pytest.mark.parametrize("from_", ["table", " table  ", "table  "])
+def test_from_strip(from_):
+    assert from_stmt(from_).strip() == "FROM table"
+
+
+@pytest.mark.parametrize("from_", ["", "  "])
+def test_invalid_from(from_):
     with pytest.raises(ValueError):
         from_stmt("    ")