Merge "Make column-level collation quoting dialect-specific"

5 files changed, 77 insertions, 5 deletions

diff --git a/lib/sqlalchemy/dialects/mssql/base.py b/lib/sqlalchemy/dialects/mssql/base.py
index b8820c2c5..840c355dc 100644
--- a/lib/sqlalchemy/dialects/mssql/base.py
+++ b/lib/sqlalchemy/dialects/mssql/base.py
@@ -1713,13 +1713,13 @@ class MSIdentifierPreparer(compiler.IdentifierPreparer):
     reserved_words = RESERVED_WORDS
 
     def __init__(self, dialect):
-        super(MSIdentifierPreparer, self).__init__(dialect, initial_quote='[',
-                                                   final_quote=']')
+        super(MSIdentifierPreparer, self).__init__(
+            dialect, initial_quote='[',
+            final_quote=']', quote_case_sensitive_collations=False)
 
     def _escape_identifier(self, value):
         return value
 
-
     def quote_schema(self, schema, force=None):
         """Prepare a quoted table and schema name."""
 
diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 7ecbd2907..560585cab 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -733,6 +733,9 @@ class SQLCompiler(Compiled):
                 self.preparer.quote(tablename) + \
                 "." + name
 
+    def visit_collation(self, element, **kw):
+        return self.preparer.format_collation(element.collation)
+
     def visit_fromclause(self, fromclause, **kwargs):
         return fromclause.name
 
@@ -2961,7 +2964,8 @@ class IdentifierPreparer(object):
     schema_for_object = schema._schema_getter(None)
 
     def __init__(self, dialect, initial_quote='"',
-                 final_quote=None, escape_quote='"', omit_schema=False):
+                 final_quote=None, escape_quote='"',
+                 quote_case_sensitive_collations=True, omit_schema=False):
         """Construct a new ``IdentifierPreparer`` object.
 
         initial_quote
@@ -2982,6 +2986,7 @@ class IdentifierPreparer(object):
         self.escape_quote = escape_quote
         self.escape_to_quote = self.escape_quote * 2
         self.omit_schema = omit_schema
+        self.quote_case_sensitive_collations = quote_case_sensitive_collations
         self._strings = {}
         self._double_percents = self.dialect.paramstyle in ('format', 'pyformat')
 
@@ -3064,6 +3069,12 @@ class IdentifierPreparer(object):
         else:
             return ident
 
+    def format_collation(self, collation_name):
+        if self.quote_case_sensitive_collations:
+            return self.quote(collation_name)
+        else:
+            return collation_name
+
     def format_sequence(self, sequence, use_schema=True):
         name = self.quote(sequence.name)
 
diff --git a/lib/sqlalchemy/sql/elements.py b/lib/sqlalchemy/sql/elements.py
index d5d079348..22636a05b 100644
--- a/lib/sqlalchemy/sql/elements.py
+++ b/lib/sqlalchemy/sql/elements.py
@@ -52,7 +52,7 @@ def collate(expression, collation):
     expr = _literal_as_binds(expression)
     return BinaryExpression(
         expr,
-        ColumnClause(collation),
+        CollationClause(collation),
         operators.collate, type_=expr.type)
 
 
@@ -3873,6 +3873,13 @@ class ColumnClause(Immutable, ColumnElement):
         return c
 
 
+class CollationClause(ColumnElement):
+    __visit_name__ = "collation"
+
+    def __init__(self, collation):
+        self.collation = collation
+
+
 class _IdentifiedClause(Executable, ClauseElement):
 
     __visit_name__ = 'identified'
diff --git a/lib/sqlalchemy/testing/requirements.py b/lib/sqlalchemy/testing/requirements.py
index f2c03a8b5..1990eb9d5 100644
--- a/lib/sqlalchemy/testing/requirements.py
+++ b/lib/sqlalchemy/testing/requirements.py
@@ -764,6 +764,20 @@ class SuiteRequirements(Requirements):
         return exclusions.closed()
 
     @property
+    def order_by_collation(self):
+        def check(config):
+            try:
+                self.get_order_by_collation(config)
+                return False
+            except NotImplementedError:
+                return True
+
+        return exclusions.skip_if(check)
+
+    def get_order_by_collation(self, config):
+        raise NotImplementedError()
+
+    @property
     def unicode_connections(self):
         """Target driver must support non-ASCII characters being passed at
         all.
diff --git a/lib/sqlalchemy/testing/suite/test_select.py b/lib/sqlalchemy/testing/suite/test_select.py
index df638c140..d9755c8f9 100644
--- a/lib/sqlalchemy/testing/suite/test_select.py
+++ b/lib/sqlalchemy/testing/suite/test_select.py
@@ -9,6 +9,46 @@ from sqlalchemy import literal_column
 from ..schema import Table, Column
 
 
+class CollateTest(fixtures.TablesTest):
+    __backend__ = True
+
+    @classmethod
+    def define_tables(cls, metadata):
+        Table("some_table", metadata,
+              Column('id', Integer, primary_key=True),
+              Column('data', String(100))
+              )
+
+    @classmethod
+    def insert_data(cls):
+        config.db.execute(
+            cls.tables.some_table.insert(),
+            [
+                {"id": 1, "data": "collate data1"},
+                {"id": 2, "data": "collate data2"},
+            ]
+        )
+
+    def _assert_result(self, select, result):
+        eq_(
+            config.db.execute(select).fetchall(),
+            result
+        )
+
+    @testing.requires.order_by_collation
+    def test_collate_order_by(self):
+        collation = testing.requires.get_order_by_collation(testing.config)
+
+        self._assert_result(
+            select([self.tables.some_table]).
+            order_by(self.tables.some_table.c.data.collate(collation).asc()),
+            [
+                (1, "collate data1"),
+                (2, "collate data2"),
+            ]
+        )
+
+
 class OrderByLabelTest(fixtures.TablesTest):
     """Test the dialect sends appropriate ORDER BY expressions when
     labels are used.