- The :func:`~.expression.column` and :func:`~.expression.table`

constructs are now importable from the "from sqlalchemy" namespace,
just like every other Core construct.
- The implicit conversion of strings to :func:`.text` constructs
when passed to most builder methods of :func:`.select` as
well as :class:`.Query` now emits a warning with just the
plain string sent.   The textual conversion still proceeds normally,
however.  The only method that accepts a string without a warning
are the "label reference" methods like order_by(), group_by();
these functions will now at compile time attempt to resolve a single
string argument to a column or label expression present in the
selectable; if none is located, the expression still renders, but
you get the warning again. The rationale here is that the implicit
conversion from string to text is more unexpected than not these days,
and it is better that the user send more direction to the Core / ORM
when passing a raw string as to what direction should be taken.
Core/ORM tutorials have been updated to go more in depth as to how text
is handled.
fixes #2992

1 files changed, 5 insertions, 7 deletions

diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py
index 090284d9f..ba557ef79 100644
--- a/lib/sqlalchemy/orm/query.py
+++ b/lib/sqlalchemy/orm/query.py
@@ -218,7 +218,7 @@ class Query(object):
     def _adapt_col_list(self, cols):
         return [
             self._adapt_clause(
-                expression._literal_as_text(o),
+                expression._literal_as_label_reference(o),
                 True, True)
             for o in cols
         ]
@@ -1282,7 +1282,7 @@ class Query(object):
 
         """
         for criterion in list(criterion):
-            criterion = expression._literal_as_text(criterion)
+            criterion = expression._expression_literal_as_text(criterion)
 
             criterion = self._adapt_clause(criterion, True, True)
 
@@ -1381,8 +1381,7 @@ class Query(object):
 
         """
 
-        if isinstance(criterion, util.string_types):
-            criterion = sql.text(criterion)
+        criterion = expression._expression_literal_as_text(criterion)
 
         if criterion is not None and \
                 not isinstance(criterion, sql.ClauseElement):
@@ -2359,8 +2358,7 @@ class Query(object):
             ORM tutorial
 
         """
-        if isinstance(statement, util.string_types):
-            statement = sql.text(statement)
+        statement = expression._expression_literal_as_text(statement)
 
         if not isinstance(statement,
                           (expression.TextClause,
@@ -2606,7 +2604,7 @@ class Query(object):
         # .with_only_columns() after we have a core select() so that
         # we get just "SELECT 1" without any entities.
         return sql.exists(self.add_columns('1').with_labels().
-                          statement.with_only_columns(['1']))
+                          statement.with_only_columns([1]))
 
     def count(self):
         """Return a count of rows this Query would return.