adding basic support for firebird, fixes #55

1 files changed, 62 insertions, 0 deletions

diff --git a/migrate/changeset/databases/firebird.py b/migrate/changeset/databases/firebird.py
new file mode 100644
index 0000000..215762c
--- /dev/null
+++ b/migrate/changeset/databases/firebird.py
@@ -0,0 +1,62 @@
+"""
+   Firebird database specific implementations of changeset classes.
+"""
+from sqlalchemy.databases import firebird as sa_base
+
+from migrate.changeset import ansisql, exceptions
+
+
+FBSchemaGenerator = sa_base.FBSchemaGenerator
+
+
+class FBColumnGenerator(FBSchemaGenerator, ansisql.ANSIColumnGenerator):
+    """Firebird column generator implementation."""
+
+
+class FBColumnDropper(ansisql.ANSIColumnDropper):
+    """Firebird column dropper implementation."""
+
+    def visit_column(self, column):
+        table = self.start_alter_table(column)
+        self.append('DROP %s' % self.preparer.format_column(column))
+        self.execute()
+
+
+class FBSchemaChanger(ansisql.ANSISchemaChanger):
+    """Firebird schema changer implementation."""
+
+    def visit_table(self, table):
+        """Rename table not supported"""
+        raise exceptions.NotSupportedError(
+            "Firebird does not support renaming tables.")
+
+    def _visit_column_name(self, table, col_name, delta):
+        new_name = delta['name']
+        self.start_alter_table(table)
+        self.append('ALTER COLUMN %s TO %s' % ((col_name), (new_name)))
+
+    def _visit_column_nullable(self, table, col_name, delta):
+        """Changing NULL is not supported"""
+        # TODO: http://www.firebirdfaq.org/faq103/
+        raise exceptions.NotSupportedError(
+            "Firebird does not support altering NULL bevahior.")
+
+
+class FBConstraintGenerator(ansisql.ANSIConstraintGenerator):
+    """Firebird constraint generator implementation."""
+
+
+class FBConstraintDropper(ansisql.ANSIConstraintDropper):
+    """Firebird constaint dropper implementation."""
+
+    def cascade_constraint(self, constraint):
+        raise exceptions.NotSupportedError(
+            "Firebird does not support cascading constraints")
+
+
+class FBDialect(ansisql.ANSIDialect):
+    columngenerator = FBColumnGenerator
+    columndropper = FBColumnDropper
+    schemachanger = FBSchemaChanger
+    constraintgenerator = FBConstraintGenerator
+    constraintdropper = FBConstraintDropper