- The argument to "ESCAPE" of a LIKE operator or similar

is passed through render_literal_value(), which may
implement escaping of backslashes.  [ticket:1400]
- Postgresql render_literal_value() is overridden which escapes
backslashes, currently applies to the ESCAPE clause
of LIKE and similar expressions.
Ultimately this will have to detect the value of
"standard_conforming_strings" for full behavior.
[ticket:1400]
- MySQL render_literal_value() is overridden which escapes
backslashes, currently applies to the ESCAPE clause
of LIKE and similar expressions.   This behavior
is derived from detecting the value of
NO_BACKSLASH_ESCAPES.  [ticket:1400]

4 files changed, 47 insertions, 9 deletions

diff --git a/lib/sqlalchemy/dialects/mysql/base.py b/lib/sqlalchemy/dialects/mysql/base.py
index c4af013fc..46e29694f 100644
--- a/lib/sqlalchemy/dialects/mysql/base.py
+++ b/lib/sqlalchemy/dialects/mysql/base.py
@@ -1196,6 +1196,12 @@ class MySQLCompiler(compiler.SQLCompiler):
 
         return 'CAST(%s AS %s)' % (self.process(cast.clause), type_)
 
+    def render_literal_value(self, value, type_):
+        value = super(MySQLCompiler, self).render_literal_value(value, type_)
+        if self.dialect._backslash_escapes:
+            value = value.replace('\\', '\\\\')
+        return value
+        
     def get_select_precolumns(self, select):
         if isinstance(select._distinct, basestring):
             return select._distinct.upper() + " "
@@ -1639,6 +1645,12 @@ class MySQLDialect(default.DefaultDialect):
     ischema_names = ischema_names
     preparer = MySQLIdentifierPreparer
     
+    # default SQL compilation settings -
+    # these are modified upon initialize(), 
+    # i.e. first connect
+    _backslash_escapes = True
+    _server_ansiquotes = False
+    
     def __init__(self, use_ansiquotes=None, **kwargs):
         default.DefaultDialect.__init__(self, **kwargs)
 
@@ -1760,7 +1772,7 @@ class MySQLDialect(default.DefaultDialect):
         self._connection_charset = self._detect_charset(connection)
         self._server_casing = self._detect_casing(connection)
         self._server_collations = self._detect_collations(connection)
-        self._server_ansiquotes = self._detect_ansiquotes(connection)
+        self._detect_ansiquotes(connection)
         if self._server_ansiquotes:
             # if ansiquotes == True, build a new IdentifierPreparer
             # with the new setting
@@ -2019,8 +2031,11 @@ class MySQLDialect(default.DefaultDialect):
                 mode_no = int(mode)
                 mode = (mode_no | 4 == mode_no) and 'ANSI_QUOTES' or ''
 
-        return 'ANSI_QUOTES' in mode
-
+        self._server_ansiquotes = 'ANSI_QUOTES' in mode
+        
+        # as of MySQL 5.0.1
+        self._backslash_escapes = 'NO_BACKSLASH_ESCAPES' not in mode
+        
     def _show_create_table(self, connection, table, charset=None,
                            full_name=None):
         """Run SHOW CREATE TABLE for a ``Table``."""
diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index 76d1122e8..8275aa1e7 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -324,12 +324,23 @@ class PGCompiler(compiler.SQLCompiler):
     def visit_ilike_op(self, binary, **kw):
         escape = binary.modifiers.get("escape", None)
         return '%s ILIKE %s' % (self.process(binary.left), self.process(binary.right)) \
-            + (escape and ' ESCAPE \'%s\'' % escape or '')
+                + (escape and 
+                        (' ESCAPE ' + self.render_literal_value(escape, None))
+                        or '')
 
     def visit_notilike_op(self, binary, **kw):
         escape = binary.modifiers.get("escape", None)
         return '%s NOT ILIKE %s' % (self.process(binary.left), self.process(binary.right)) \
-            + (escape and ' ESCAPE \'%s\'' % escape or '')
+                + (escape and 
+                        (' ESCAPE ' + self.render_literal_value(escape, None))
+                        or '')
+
+    def render_literal_value(self, value, type_):
+        value = super(PGCompiler, self).render_literal_value(value, type_)
+        # TODO: need to inspect "standard_conforming_strings"
+        if self.dialect._backslash_escapes:
+            value = value.replace('\\', '\\\\')
+        return value
 
     def visit_sequence(self, seq):
         if seq.optional:
@@ -625,6 +636,9 @@ class PGDialect(default.DefaultDialect):
     inspector = PGInspector
     isolation_level = None
 
+    # TODO: need to inspect "standard_conforming_strings"
+    _backslash_escapes = True
+
     def __init__(self, isolation_level=None, **kwargs):
         default.DefaultDialect.__init__(self, **kwargs)
         self.isolation_level = isolation_level
diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index b4992eec3..c54931b87 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -494,28 +494,36 @@ class SQLCompiler(engine.Compiled):
         return '%s LIKE %s' % (
                                     self.process(binary.left, **kw), 
                                     self.process(binary.right, **kw)) \
-            + (escape and ' ESCAPE \'%s\'' % escape or '')
+            + (escape and 
+                    (' ESCAPE ' + self.render_literal_value(escape, None))
+                    or '')
 
     def visit_notlike_op(self, binary, **kw):
         escape = binary.modifiers.get("escape", None)
         return '%s NOT LIKE %s' % (
                                     self.process(binary.left, **kw), 
                                     self.process(binary.right, **kw)) \
-            + (escape and ' ESCAPE \'%s\'' % escape or '')
+            + (escape and 
+                    (' ESCAPE ' + self.render_literal_value(escape, None))
+                    or '')
         
     def visit_ilike_op(self, binary, **kw):
         escape = binary.modifiers.get("escape", None)
         return 'lower(%s) LIKE lower(%s)' % (
                                             self.process(binary.left, **kw), 
                                             self.process(binary.right, **kw)) \
-            + (escape and ' ESCAPE \'%s\'' % escape or '')
+            + (escape and 
+                    (' ESCAPE ' + self.render_literal_value(escape, None))
+                    or '')
     
     def visit_notilike_op(self, binary, **kw):
         escape = binary.modifiers.get("escape", None)
         return 'lower(%s) NOT LIKE lower(%s)' % (
                                             self.process(binary.left, **kw), 
                                             self.process(binary.right, **kw)) \
-            + (escape and ' ESCAPE \'%s\'' % escape or '')
+            + (escape and 
+                    (' ESCAPE ' + self.render_literal_value(escape, None))
+                    or '')
         
     def _operator_dispatch(self, operator, element, fn, **kw):
         if util.callable(operator):
diff --git a/lib/sqlalchemy/types.py b/lib/sqlalchemy/types.py
index 84bd85ff2..d8a176f1f 100644
--- a/lib/sqlalchemy/types.py
+++ b/lib/sqlalchemy/types.py
@@ -1796,6 +1796,7 @@ class BOOLEAN(Boolean):
 
 NULLTYPE = NullType()
 BOOLEANTYPE = Boolean()
+STRINGTYPE = String()
 
 # using VARCHAR/NCHAR so that we dont get the genericized "String"
 # type which usually resolves to TEXT/CLOB