From 39837686b068a6e7016169f31a96a058546e4bdd Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 19 Jan 2016 16:47:16 -0500
Subject: - calling str() on a core sql construct has been made more
 "friendly", when the construct contains non-standard sql elements such as
 returning, array index operations, or dialect-specific or custom datatypes. 
 a string is now returned in these cases rendering an approximation of the
 construct (typically the postgresql-style version of it) rather than raising
 an error. fixes #3631 - add within_group to top-level imports - add
 eq_ignore_whitespace to sqlalchemy.testing imports

---
 lib/sqlalchemy/sql/__init__.py |  1 +
 lib/sqlalchemy/sql/compiler.py | 35 +++++++++++++++++++++++++++++++++++
 lib/sqlalchemy/sql/elements.py |  2 +-
 3 files changed, 37 insertions(+), 1 deletion(-)

(limited to 'lib/sqlalchemy/sql')

diff --git a/lib/sqlalchemy/sql/__init__.py b/lib/sqlalchemy/sql/__init__.py
index fa2cf2399..f4ad3ec00 100644
--- a/lib/sqlalchemy/sql/__init__.py
+++ b/lib/sqlalchemy/sql/__init__.py
@@ -66,6 +66,7 @@ from .expression import (
     union,
     union_all,
     update,
+    within_group
 )
 
 from .visitors import ClauseVisitor
diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index c5f87cc33..076ae53b2 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -2118,6 +2118,30 @@ class SQLCompiler(Compiled):
             self.preparer.format_savepoint(savepoint_stmt)
 
 
+class StrSQLCompiler(SQLCompiler):
+    """"a compiler subclass with a few non-standard SQL features allowed.
+
+    Used for stringification of SQL statements when a real dialect is not
+    available.
+
+    """
+
+    def visit_getitem_binary(self, binary, operator, **kw):
+        return "%s[%s]" % (
+            self.process(binary.left, **kw),
+            self.process(binary.right, **kw)
+        )
+
+    def returning_clause(self, stmt, returning_cols):
+
+        columns = [
+            self._label_select_column(None, c, True, False, {})
+            for c in elements._select_iterables(returning_cols)
+        ]
+
+        return 'RETURNING ' + ', '.join(columns)
+
+
 class DDLCompiler(Compiled):
 
     @util.memoized_property
@@ -2640,6 +2664,17 @@ class GenericTypeCompiler(TypeCompiler):
         return type_.get_col_spec(**kw)
 
 
+class StrSQLTypeCompiler(GenericTypeCompiler):
+    def __getattr__(self, key):
+        if key.startswith("visit_"):
+            return self._visit_unknown
+        else:
+            raise AttributeError(key)
+
+    def _visit_unknown(self, type_, **kw):
+        return "%s" % type_.__class__.__name__
+
+
 class IdentifierPreparer(object):
 
     """Handle quoting and case-folding of identifiers based on options."""
diff --git a/lib/sqlalchemy/sql/elements.py b/lib/sqlalchemy/sql/elements.py
index de17aabb3..fe2fecce8 100644
--- a/lib/sqlalchemy/sql/elements.py
+++ b/lib/sqlalchemy/sql/elements.py
@@ -429,7 +429,7 @@ class ClauseElement(Visitable):
                 dialect = self.bind.dialect
                 bind = self.bind
             else:
-                dialect = default.DefaultDialect()
+                dialect = default.StrCompileDialect()
         return self._compiler(dialect, bind=bind, **kw)
 
     def _compiler(self, dialect, **kw):
-- 
cgit v1.2.1