Database Class

Class DbClass is derived from ~pyrseas.dbobject.DbSchemaObject and represents a table, view or sequence as defined in the PostgreSQL pg_class catalog. Note: Views are not implemented yet.

Sequence

Class Sequence is derived from DbClass and represents a sequence generator. Its keylist attributes are the schema name and the sequence name.

A Sequence has the following attributes: start_value, increment_by, max_value, min_value and cache_value.

The map returned by to_map and expected as argument by diff_map has the following structure:

{'sequence seq1':
    {'start_value': 1,
     'increment_by': 1,
     'max_value': None,
     'min_value': None,
     'cache_value': 1
    }
}

Only the inner dictionary is passed to diff_map. The values are defaults so in practice an empty dictionary is also acceptable.

Table

Class Table is derived from DbClass and represents a database table. Its keylist attributes are the schema name and the table name.

The map returned by to_map and expected as argument by diff_map has a structure similar to the following:

{'table t1':
    {'columns':
        [
        {'c1': {'type': 'integer', 'not_null': True}},
        {'c2': {'type': 'text'}},
        {'c3': {'type': 'smallint'}},
        {'c4': {'type': 'date', 'default': 'now()'}}
        ],
     'description': "this is the comment for table t1",
     'primary_key':
        {'t1_prim_key':
            {'columns': ['c1', 'c2'], 'access_method': 'btree'}
        },
     'foreign_keys':
        {'t1_fgn_key1':
            {'columns': ['c2', 'c3'],
              'references':
                  {'table': 't2', 'columns': ['pc2', 'pc1']}
            },
         't1_fgn_key2':
            {'columns': ['c2'],
             'references': {'table': 't3', 'columns': ['qc1']}
            }
        },
     'unique_constraints': {...},
     'indexes': {...}
    }
}

The values for unique_constraints and indexes follow a pattern similar to primary_key, but there can be more than one such specification.

View

Class View is derived from DbClass and represents a database view. Its keylist attributes are the schema name and the view name.

The map returned by to_map and expected as argument by diff_map has a structure similar to the following:

{'view v1':
    {'definition': " SELECT ...;",
     'description': "this is the comment for view v1"
    }
}

Class Dictionary

Class ClassDict is derived from ~pyrseas.dbobject.DbObjectDict and represents the collection of tables, views and sequences in a database.