From 3dd5d834ad6d3ae7f515ff20f3b8756d46e2347f Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Thu, 14 Sep 2006 16:41:18 +0000
Subject: [PATCH] added extract() function to sql dialect

---
 CHANGES               | 1 +
 lib/sqlalchemy/sql.py | 8 ++++++--
 test/sql/select.py    | 6 ++++++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index 67a359b319..3f664c4989 100644
--- a/CHANGES
+++ b/CHANGES
@@ -15,6 +15,7 @@ when version_id_col is in effect and query.with_lockmode()
 is used to get() an instance thats already loaded
 - fixed bug where Connection wouldnt lose its Transaction
 after commit/rollback
+- added extract() function to sql dialect
 
 0.2.8
 - cleanup on connection methods + documentation.  custom DBAPI
diff --git a/lib/sqlalchemy/sql.py b/lib/sqlalchemy/sql.py
index ab371dcb91..1f3d3575ed 100644
--- a/lib/sqlalchemy/sql.py
+++ b/lib/sqlalchemy/sql.py
@@ -10,7 +10,7 @@ from sqlalchemy import types as sqltypes
 import string, re, random, sets
 types = __import__('types')
 
-__all__ = ['text', 'table', 'column', 'func', 'select', 'update', 'insert', 'delete', 'join', 'and_', 'or_', 'not_', 'between_', 'case', 'cast', 'union', 'union_all', 'null', 'desc', 'asc', 'outerjoin', 'alias', 'subquery', 'literal', 'bindparam', 'exists']
+__all__ = ['text', 'table', 'column', 'func', 'select', 'update', 'insert', 'delete', 'join', 'and_', 'or_', 'not_', 'between_', 'case', 'cast', 'union', 'union_all', 'null', 'desc', 'asc', 'outerjoin', 'alias', 'subquery', 'literal', 'bindparam', 'exists', 'extract']
 
 def desc(column):
     """returns a descending ORDER BY clause element, e.g.:
@@ -155,7 +155,11 @@ def cast(clause, totype, **kwargs):
     """
     return Cast(clause, totype, **kwargs)
 
-
+def extract(field, expr):
+    """return extract(field FROM expr)"""
+    expr = BinaryClause(text(field), expr, "FROM")
+    return func.extract(expr)
+    
 def exists(*args, **params):
     params['correlate'] = True
     s = select(*args, **params)
diff --git a/test/sql/select.py b/test/sql/select.py
index 8a5fc302cc..586184b4a7 100644
--- a/test/sql/select.py
+++ b/test/sql/select.py
@@ -404,6 +404,12 @@ FROM mytable, myothertable WHERE foo.id = foofoo(lala) AND datetime(foo) = Today
 
         # test a dotted func off the engine itself
         self.runtest(func.lala.hoho(7), "lala.hoho(:hoho)")
+    
+    def testextract(self):
+        """test the EXTRACT function"""
+        self.runtest(select([extract("month", table3.c.otherstuff)]), "SELECT extract(month FROM thirdtable.otherstuff) FROM thirdtable")
+        
+        self.runtest(select([extract("day", func.to_date("03/20/2005", "MM/DD/YYYY"))]), "SELECT extract(day FROM to_date(:to_date, :to_da_1))")
         
     def testjoin(self):
         self.runtest(
-- 
2.47.2