From: Jay Freeman (saurik) <saurik@saurik.com>
Date: Fri, 30 Jul 2010 07:21:07 +0000 (+0000)
Subject: Add exists(), refactoring yank() to take an argument for offset (required as a utility).
X-Git-Url: https://git.saurik.com/cyql.git/commitdiff_plain/f1df255a1450b9f5040a075f11310e12713cd46d?hp=229bbf8c4928ba0ce6d47fbb0b102c1f20eac8c0

Add exists(), refactoring yank() to take an argument for offset (required as a utility).
---

diff --git a/__init__.py b/__init__.py
index 2bddbe4..bda044b 100644
--- a/__init__.py
+++ b/__init__.py
@@ -56,8 +56,8 @@ class transaction(object):
         with self.connection.execute(statement, 1) as cursor:
             return cursor.fetchall()
 
-    def yank(self, statement):
-        with self.connection.execute(statement, 1) as cursor:
+    def yank(self, statement, offset=0):
+        with self.connection.execute(statement, 1 + offset) as cursor:
             rows = cursor.fetchall()
             return rows[0] if len(rows) != 0 else None
 
@@ -65,6 +65,13 @@ class transaction(object):
         with self.connection.execute(statement, 1) as cursor:
             pass
 
+    def exists(self, statement):
+        return yank('''
+            select exists (
+                {statement}
+            )
+        ''')[0]
+
 @contextmanager
 def connect(dsn):
     attempt = 0