Add SKIP LOCKED support for Postgresql, Oracle

This adds `SELECT ... FOR UPDATE SKIP LOCKED`/
`SELECT ... FOR SHARE SKIP LOCKED` rendering.

Change-Id: Id1dc4f1cafc1de23f397a6f73d54ab2c58d5910d
Pull-request: https://bitbucket.org/zzzeek/sqlalchemy/pull-requests/86

1 files changed, 22 insertions, 0 deletions

diff --git a/test/dialect/postgresql/test_compiler.py b/test/dialect/postgresql/test_compiler.py
index c20e48b01..c061cfaf1 100644
--- a/test/dialect/postgresql/test_compiler.py
+++ b/test/dialect/postgresql/test_compiler.py
@@ -606,6 +606,13 @@ class CompileTest(fixtures.TestBase, AssertsCompiledSQL):
             "FROM mytable WHERE mytable.myid = %(myid_1)s FOR UPDATE NOWAIT")
 
         self.assert_compile(
+            table1.select(table1.c.myid == 7).
+            with_for_update(skip_locked=True),
+            "SELECT mytable.myid, mytable.name, mytable.description "
+            "FROM mytable WHERE mytable.myid = %(myid_1)s "
+            "FOR UPDATE SKIP LOCKED")
+
+        self.assert_compile(
             table1.select(table1.c.myid == 7).with_for_update(read=True),
             "SELECT mytable.myid, mytable.name, mytable.description "
             "FROM mytable WHERE mytable.myid = %(myid_1)s FOR SHARE")
@@ -618,6 +625,13 @@ class CompileTest(fixtures.TestBase, AssertsCompiledSQL):
 
         self.assert_compile(
             table1.select(table1.c.myid == 7).
+            with_for_update(read=True, skip_locked=True),
+            "SELECT mytable.myid, mytable.name, mytable.description "
+            "FROM mytable WHERE mytable.myid = %(myid_1)s "
+            "FOR SHARE SKIP LOCKED")
+
+        self.assert_compile(
+            table1.select(table1.c.myid == 7).
             with_for_update(of=table1.c.myid),
             "SELECT mytable.myid, mytable.name, mytable.description "
             "FROM mytable WHERE mytable.myid = %(myid_1)s "
@@ -645,6 +659,14 @@ class CompileTest(fixtures.TestBase, AssertsCompiledSQL):
             "FROM mytable WHERE mytable.myid = %(myid_1)s "
             "FOR SHARE OF mytable NOWAIT")
 
+        self.assert_compile(
+            table1.select(table1.c.myid == 7).
+            with_for_update(read=True, skip_locked=True,
+                            of=[table1.c.myid, table1.c.name]),
+            "SELECT mytable.myid, mytable.name, mytable.description "
+            "FROM mytable WHERE mytable.myid = %(myid_1)s "
+            "FOR SHARE OF mytable SKIP LOCKED")
+
         ta = table1.alias()
         self.assert_compile(
             ta.select(ta.c.myid == 7).