- [feature] Reworked the startswith(), endswith(),

    contains() operators to do a better job with
    negation (NOT LIKE), and also to assemble them
    at compilation time so that their rendered SQL
    can be altered, such as in the case for Firebird
    STARTING WITH [ticket:2470]
  - [feature] firebird - The "startswith()" operator renders
    as "STARTING WITH", "~startswith()" renders
    as "NOT STARTING WITH", using FB's more efficient
    operator.  [ticket:2470]

1 files changed, 45 insertions, 1 deletions

diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 8e4f0288f..297cd9adb 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -24,7 +24,7 @@ To generate user-defined SQL strings, see
 
 import re
 import sys
-from .. import schema, engine, util, exc
+from .. import schema, engine, util, exc, types
 from . import (
     operators, functions, util as sql_util, visitors, expression as sql
 )
@@ -670,6 +670,50 @@ class SQLCompiler(engine.Compiled):
     def _generate_generic_unary_modifier(self, unary, opstring, **kw):
         return unary.element._compiler_dispatch(self, **kw) + opstring
 
+    @util.memoized_property
+    def _like_percent_literal(self):
+        return sql.literal_column("'%'", type_=types.String())
+
+    def visit_contains_op_binary(self, binary, operator, **kw):
+        binary = binary._clone()
+        percent = self._like_percent_literal
+        binary.right = percent.__add__(binary.right).__add__(percent)
+        return self.visit_like_op_binary(binary, operator, **kw)
+
+    def visit_notcontains_op_binary(self, binary, operator, **kw):
+        binary = binary._clone()
+        percent = self._like_percent_literal
+        binary.right = percent.__add__(binary.right).__add__(percent)
+        return self.visit_notlike_op_binary(binary, operator, **kw)
+
+    def visit_startswith_op_binary(self, binary, operator, **kw):
+        binary = binary._clone()
+        percent = self._like_percent_literal
+        binary.right = percent.__radd__(
+                    binary.right
+                )
+        return self.visit_like_op_binary(binary, operator, **kw)
+
+    def visit_notstartswith_op_binary(self, binary, operator, **kw):
+        binary = binary._clone()
+        percent = self._like_percent_literal
+        binary.right = percent.__radd__(
+                    binary.right
+                )
+        return self.visit_notlike_op_binary(binary, operator, **kw)
+
+    def visit_endswith_op_binary(self, binary, operator, **kw):
+        binary = binary._clone()
+        percent = self._like_percent_literal
+        binary.right = percent.__add__(binary.right)
+        return self.visit_like_op_binary(binary, operator, **kw)
+
+    def visit_notendswith_op_binary(self, binary, operator, **kw):
+        binary = binary._clone()
+        percent = self._like_percent_literal
+        binary.right = percent.__add__(binary.right)
+        return self.visit_notlike_op_binary(binary, operator, **kw)
+
     def visit_like_op_binary(self, binary, operator, **kw):
         escape = binary.modifiers.get("escape", None)
         return '%s LIKE %s' % (