mark ALTER TABLE ADD FOREIGN KEY as unsupported by SQLite

update corresponding test case

migrate/changeset/databases/sqlite.py

@@ -77,6 +77,17 @@ class SQLiteConstraintGenerator(ansisql.ANSIConstraintGenerator):
         self.execute()
 
 
+class SQLiteFKGenerator(SQLiteSchemaChanger, ansisql.ANSIFKGenerator):
+    def visit_column(self, column):
+        """Create foreign keys for a column (table already exists); #32"""
+
+        if self.fk:
+            self._not_supported("ALTER TABLE ADD FOREIGN KEY")
+
+        if self.buffer.getvalue() !='':
+            self.execute()
+
+
 class SQLiteConstraintDropper(ansisql.ANSIColumnDropper):
 
     def visit_migrate_primary_key_constraint(self, constraint):
@@ -93,3 +104,4 @@ class SQLiteDialect(ansisql.ANSIDialect):
     schemachanger = SQLiteSchemaChanger
     constraintgenerator = SQLiteConstraintGenerator
     constraintdropper = SQLiteConstraintDropper
+    columnfkgenerator = SQLiteFKGenerator

test/changeset/test_changeset.py

@@ -168,20 +168,14 @@ class TestAddDropColumn(fixture.DB):
             if self.engine.has_table(reftable.name):
                 reftable.drop()
             return ret
+        if self.url.startswith('sqlite'):
+            self.assertRaises(changeset.exceptions.NotSupportedError,
+                              self.run_, add_func, drop_func, Integer,
+                              ForeignKey(reftable.c.id))
+        else:
             return self.run_(add_func,drop_func,Integer,
                              ForeignKey(reftable.c.id))
 
-    #@fixture.usedb()
-    #def xtest_pk(self):
-    #    """Can create/drop primary key columns
-    #    Not supported
-    #    """
-    #    def add_func(col):
-    #        create_column(col,self.table)
-    #    def drop_func(col):
-    #        drop_column(col,self.table)
-    #    # Primary key length is checked in run_
-    #    return self.run_(add_func,drop_func,Integer,primary_key=True)
 
 class TestRename(fixture.DB):
     level=fixture.DB.CONNECT