From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Fri, 4 Feb 2011 22:37:36 +0000 (-0500)
Subject: - When explicit sequence execution derives the name
X-Git-Tag: rel_0_7b1~37
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d5cc2f83c1183eb65d0daac3532a1645d0cd9513;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

- When explicit sequence execution derives the name
of the auto-generated sequence of a SERIAL column,
which currently only occurs if implicit_returning=False,
now accommodates if the table + column name is greater
than 63 characters using the same logic Postgresql uses.
[ticket:1083]
---

diff --git a/CHANGES b/CHANGES
index 7f5ef2f6fd..a848035efd 100644
--- a/CHANGES
+++ b/CHANGES
@@ -206,6 +206,14 @@ CHANGES
     the extension compiles and runs on Python 2.4.
     [ticket:2023]
 
+- postgresql
+  - When explicit sequence execution derives the name 
+    of the auto-generated sequence of a SERIAL column, 
+    which currently only occurs if implicit_returning=False, 
+    now accommodates if the table + column name is greater 
+    than 63 characters using the same logic Postgresql uses.  
+    [ticket:1083]
+
 0.6.6
 =====
 - orm
diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index 4e7e114c9d..22d269cdf0 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -706,14 +706,23 @@ class PGExecutionContext(default.DefaultExecutionContext):
                 # execute the sequence associated with a SERIAL primary 
                 # key column. for non-primary-key SERIAL, the ID just
                 # generates server side.
-                sch = column.table.schema
 
+                try:
+                    seq_name = column._postgresql_seq_name
+                except AttributeError:
+                    tab = column.table.name 
+                    col = column.name 
+                    tab = tab[0:29 + max(0, (29 - len(col)))] 
+                    col = col[0:29 + max(0, (29 - len(tab)))] 
+                    column._postgresql_seq_name = seq_name = "%s_%s_seq" % (tab, col)
+
+                sch = column.table.schema
                 if sch is not None:
-                    exc = "select nextval('\"%s\".\"%s_%s_seq\"')" % \
-                            (sch, column.table.name, column.name)
+                    exc = "select nextval('\"%s\".\"%s\"')" % \
+                            (sch, seq_name)
                 else:
-                    exc = "select nextval('\"%s_%s_seq\"')" % \
-                            (column.table.name, column.name)
+                    exc = "select nextval('\"%s\"')" % \
+                            (seq_name, )
 
                 return self._execute_scalar(exc, column.type)
 
diff --git a/test/dialect/test_postgresql.py b/test/dialect/test_postgresql.py
index f8ca65e603..9aa281979d 100644
--- a/test/dialect/test_postgresql.py
+++ b/test/dialect/test_postgresql.py
@@ -17,7 +17,7 @@ import logging
 
 class SequenceTest(TestBase, AssertsCompiledSQL):
 
-    def test_basic(self):
+    def test_format(self):
         seq = Sequence('my_seq_no_schema')
         dialect = postgresql.PGDialect()
         assert dialect.identifier_preparer.format_sequence(seq) \
@@ -29,6 +29,24 @@ class SequenceTest(TestBase, AssertsCompiledSQL):
         assert dialect.identifier_preparer.format_sequence(seq) \
             == '"Some_Schema"."My_Seq"'
 
+    @testing.only_on('postgresql', 'foo')
+    @testing.provide_metadata
+    def test_reverse_eng_name(self):
+        engine = engines.testing_engine(options=dict(implicit_returning=False))
+        for tname, cname in [
+            ('tb1' * 30, 'abc'),
+            ('tb2', 'abc' * 30),
+            ('tb3' * 30, 'abc' * 30),
+            ('tb4', 'abc'),
+        ]:
+            t = Table(tname[:57],
+                metadata,
+                Column(cname[:57], Integer, primary_key=True)
+            )
+            t.create(engine)
+            r = engine.execute(t.insert())
+            assert r.inserted_primary_key == [1]
+
 class CompileTest(TestBase, AssertsCompiledSQL):
 
     __dialect__ = postgresql.dialect()