Make column-level collation quoting dialect-specific

Fixed regression in 1.2 where newly repaired quoting
of collation names in :ticket:`3785` breaks SQL Server,
which explicitly does not understand a quoted collation
name.   Whether or not mixed-case collation names are
quoted or not is now deferred down to a dialect-level
decision so that each dialect can prepare these identifiers
directly.

Change-Id: Iaf0a8123d9bf4711219e320896bb28c5d2649304
Fixes: #4154

2 files changed, 28 insertions, 2 deletions

diff --git a/test/sql/test_compiler.py b/test/sql/test_compiler.py
index 988230ac5..25eb2b24b 100644
--- a/test/sql/test_compiler.py
+++ b/test/sql/test_compiler.py
@@ -1450,6 +1450,25 @@ class SelectTest(fixtures.TestBase, AssertsCompiledSQL):
                 []).compile,
             dialect=empty_in_dialect)
 
+    def test_collate(self):
+        # columns clause
+        self.assert_compile(
+            select([column('x').collate('bar')]),
+            "SELECT x COLLATE bar AS anon_1"
+        )
+
+        # WHERE clause
+        self.assert_compile(
+            select([column('x')]).where(column('x').collate('bar') == 'foo'),
+            "SELECT x WHERE (x COLLATE bar) = :param_1"
+        )
+
+        # ORDER BY clause
+        self.assert_compile(
+            select([column('x')]).order_by(column('x').collate('bar')),
+            "SELECT x ORDER BY x COLLATE bar"
+        )
+
     def test_literal(self):
 
         self.assert_compile(select([literal('foo')]),
diff --git a/test/sql/test_quote.py b/test/sql/test_quote.py
index 477fca783..a51e14244 100644
--- a/test/sql/test_quote.py
+++ b/test/sql/test_quote.py
@@ -1,6 +1,6 @@
 from sqlalchemy import MetaData, Table, Column, Integer, select, \
     ForeignKey, Index, CheckConstraint, inspect, column
-from sqlalchemy import sql, schema
+from sqlalchemy import sql, schema, types as sqltypes
 from sqlalchemy.sql import compiler
 from sqlalchemy.testing import fixtures, AssertsCompiledSQL, eq_
 from sqlalchemy import testing
@@ -462,7 +462,8 @@ class QuoteTest(fixtures.TestBase, AssertsCompiledSQL):
 
         self.assert_compile(
             column('foo').collate('fr_FR'),
-            'foo COLLATE "fr_FR"'
+            'foo COLLATE "fr_FR"',
+            dialect="postgresql"
         )
 
         self.assert_compile(
@@ -471,6 +472,12 @@ class QuoteTest(fixtures.TestBase, AssertsCompiledSQL):
             dialect="mysql"
         )
 
+        self.assert_compile(
+            column('foo').collate('SQL_Latin1_General_CP1_CI_AS'),
+            'foo COLLATE SQL_Latin1_General_CP1_CI_AS',
+            dialect="mssql"
+        )
+
     def test_join(self):
         # Lower case names, should not quote
         metadata = MetaData()