diff options
| -rw-r--r-- | django/db/backends/creation.py | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/django/db/backends/creation.py b/django/db/backends/creation.py index f6041c73f3..53874f9f73 100644 --- a/django/db/backends/creation.py +++ b/django/db/backends/creation.py @@ -25,6 +25,10 @@ class BaseDatabaseCreation(object): def __init__(self, connection): self.connection = connection + def _digest(self, *args): + "Generate a 32 bit digest of a set of arguments that can be used to shorten identifying names" + return '%x' % (abs(hash(args)) % (1<<32)) + def sql_create_model(self, model, style, known_models=set()): """ Returns the SQL required to create a single model, as a tuple of: @@ -128,7 +132,7 @@ class BaseDatabaseCreation(object): col = opts.get_field(f.rel.field_name).column # For MySQL, r_name must be unique in the first 64 characters. # So we are careful with character usage here. - r_name = '%s_refs_%s_%x' % (r_col, col, abs(hash((r_table, table)))) + r_name = '%s_refs_%s_%s' % (r_col, col, self._digest(r_table, table)) final_output.append(style.SQL_KEYWORD('ALTER TABLE') + ' %s ADD CONSTRAINT %s FOREIGN KEY (%s) REFERENCES %s (%s)%s;' % \ (qn(r_table), qn(truncate_name(r_name, self.connection.ops.max_name_length())), qn(r_col), qn(table), qn(col), @@ -187,8 +191,7 @@ class BaseDatabaseCreation(object): output.append('\n'.join(table_output)) for r_table, r_col, table, col in deferred: - r_name = '%s_refs_%s_%x' % (r_col, col, - abs(hash((r_table, table)))) + r_name = '%s_refs_%s_%s' % (r_col, col, self._digest(r_table, table)) output.append(style.SQL_KEYWORD('ALTER TABLE') + ' %s ADD CONSTRAINT %s FOREIGN KEY (%s) REFERENCES %s (%s)%s;' % (qn(r_table), qn(truncate_name(r_name, self.connection.ops.max_name_length())), @@ -289,7 +292,7 @@ class BaseDatabaseCreation(object): col = f.column r_table = model._meta.db_table r_col = model._meta.get_field(f.rel.field_name).column - r_name = '%s_refs_%s_%x' % (col, r_col, abs(hash((table, r_table)))) + r_name = '%s_refs_%s_%s' % (col, r_col, self._digest(table, r_table)) output.append('%s %s %s %s;' % \ (style.SQL_KEYWORD('ALTER TABLE'), style.SQL_TABLE(qn(table)), |