diff options
Diffstat (limited to 'lib/sqlalchemy/engine/reflection.py')
| -rw-r--r-- | lib/sqlalchemy/engine/reflection.py | 82 |
1 files changed, 80 insertions, 2 deletions
diff --git a/lib/sqlalchemy/engine/reflection.py b/lib/sqlalchemy/engine/reflection.py index 2a1def86a..6e102aad6 100644 --- a/lib/sqlalchemy/engine/reflection.py +++ b/lib/sqlalchemy/engine/reflection.py @@ -173,7 +173,14 @@ class Inspector(object): passed as ``None``. For special quoting, use :class:`.quoted_name`. :param order_by: Optional, may be the string "foreign_key" to sort - the result on foreign key dependencies. + the result on foreign key dependencies. Does not automatically + resolve cycles, and will raise :class:`.CircularDependencyError` + if cycles exist. + + .. deprecated:: 1.0.0 - see + :meth:`.Inspector.get_sorted_table_and_fkc_names` for a version + of this which resolves foreign key cycles between tables + automatically. .. versionchanged:: 0.8 the "foreign_key" sorting sorts tables in order of dependee to dependent; that is, in creation @@ -183,6 +190,8 @@ class Inspector(object): .. seealso:: + :meth:`.Inspector.get_sorted_table_and_fkc_names` + :attr:`.MetaData.sorted_tables` """ @@ -201,6 +210,64 @@ class Inspector(object): tnames = list(topological.sort(tuples, tnames)) return tnames + def get_sorted_table_and_fkc_names(self, schema=None): + """Return dependency-sorted table and foreign key constraint names in + referred to within a particular schema. + + This will yield 2-tuples of + ``(tablename, [(tname, fkname), (tname, fkname), ...])`` + consisting of table names in CREATE order grouped with the foreign key + constraint names that are not detected as belonging to a cycle. + The final element + will be ``(None, [(tname, fkname), (tname, fkname), ..])`` + which will consist of remaining + foreign key constraint names that would require a separate CREATE + step after-the-fact, based on dependencies between tables. + + .. versionadded:: 1.0.- + + .. seealso:: + + :meth:`.Inspector.get_table_names` + + :func:`.sort_tables_and_constraints` - similar method which works + with an already-given :class:`.MetaData`. + + """ + if hasattr(self.dialect, 'get_table_names'): + tnames = self.dialect.get_table_names( + self.bind, schema, info_cache=self.info_cache) + else: + tnames = self.engine.table_names(schema) + + tuples = set() + remaining_fkcs = set() + + fknames_for_table = {} + for tname in tnames: + fkeys = self.get_foreign_keys(tname, schema) + fknames_for_table[tname] = set( + [fk['name'] for fk in fkeys] + ) + for fkey in fkeys: + if tname != fkey['referred_table']: + tuples.add((fkey['referred_table'], tname)) + try: + candidate_sort = list(topological.sort(tuples, tnames)) + except exc.CircularDependencyError as err: + for edge in err.edges: + tuples.remove(edge) + remaining_fkcs.update( + (edge[1], fkc) + for fkc in fknames_for_table[edge[1]] + ) + + candidate_sort = list(topological.sort(tuples, tnames)) + return [ + (tname, fknames_for_table[tname].difference(remaining_fkcs)) + for tname in candidate_sort + ] + [(None, list(remaining_fkcs))] + def get_temp_table_names(self): """return a list of temporary table names for the current bind. @@ -394,6 +461,12 @@ class Inspector(object): unique boolean + dialect_options + dict of dialect-specific index options. May not be present + for all dialects. + + .. versionadded:: 1.0.0 + :param table_name: string name of the table. For special quoting, use :class:`.quoted_name`. @@ -642,6 +715,8 @@ class Inspector(object): columns = index_d['column_names'] unique = index_d['unique'] flavor = index_d.get('type', 'index') + dialect_options = index_d.get('dialect_options', {}) + duplicates = index_d.get('duplicates_constraint') if include_columns and \ not set(columns).issubset(include_columns): @@ -667,7 +742,10 @@ class Inspector(object): else: idx_cols.append(idx_col) - sa_schema.Index(name, *idx_cols, **dict(unique=unique)) + sa_schema.Index( + name, *idx_cols, + **dict(list(dialect_options.items()) + [('unique', unique)]) + ) def _reflect_unique_constraints( self, table_name, schema, table, cols_by_orig_name, |