Construct a GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY DDL construct to accompany a :class:`_schema.Column`. See the :class:`.Sequence` documentation for a complete description of most parameters. .. note:: MSSQL supports this construct as the preferr
(
self,
always: bool = False,
on_null: Optional[bool] = None,
start: Optional[int] = None,
increment: Optional[int] = None,
minvalue: Optional[int] = None,
maxvalue: Optional[int] = None,
nominvalue: Optional[bool] = None,
nomaxvalue: Optional[bool] = None,
cycle: Optional[bool] = None,
cache: Optional[int] = None,
order: Optional[bool] = None,
)
| 6098 | is_identity = True |
| 6099 | |
| 6100 | def __init__( |
| 6101 | self, |
| 6102 | always: bool = False, |
| 6103 | on_null: Optional[bool] = None, |
| 6104 | start: Optional[int] = None, |
| 6105 | increment: Optional[int] = None, |
| 6106 | minvalue: Optional[int] = None, |
| 6107 | maxvalue: Optional[int] = None, |
| 6108 | nominvalue: Optional[bool] = None, |
| 6109 | nomaxvalue: Optional[bool] = None, |
| 6110 | cycle: Optional[bool] = None, |
| 6111 | cache: Optional[int] = None, |
| 6112 | order: Optional[bool] = None, |
| 6113 | ) -> None: |
| 6114 | """Construct a GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY DDL |
| 6115 | construct to accompany a :class:`_schema.Column`. |
| 6116 | |
| 6117 | See the :class:`.Sequence` documentation for a complete description |
| 6118 | of most parameters. |
| 6119 | |
| 6120 | .. note:: |
| 6121 | MSSQL supports this construct as the preferred alternative to |
| 6122 | generate an IDENTITY on a column, but it uses non standard |
| 6123 | syntax that only support :paramref:`_schema.Identity.start` |
| 6124 | and :paramref:`_schema.Identity.increment`. |
| 6125 | All other parameters are ignored. |
| 6126 | |
| 6127 | :param always: |
| 6128 | A boolean, that indicates the type of identity column. |
| 6129 | If ``False`` is specified, the default, then the user-specified |
| 6130 | value takes precedence. |
| 6131 | If ``True`` is specified, a user-specified value is not accepted ( |
| 6132 | on some backends, like PostgreSQL, OVERRIDING SYSTEM VALUE, or |
| 6133 | similar, may be specified in an INSERT to override the sequence |
| 6134 | value). |
| 6135 | Some backends also have a default value for this parameter, |
| 6136 | ``None`` can be used to omit rendering this part in the DDL. It |
| 6137 | will be treated as ``False`` if a backend does not have a default |
| 6138 | value. |
| 6139 | |
| 6140 | :param on_null: |
| 6141 | Set to ``True`` to specify ON NULL in conjunction with a |
| 6142 | ``always=False`` identity column. This option is only supported on |
| 6143 | some backends, like Oracle Database. |
| 6144 | |
| 6145 | :param start: the starting index of the sequence. |
| 6146 | :param increment: the increment value of the sequence. |
| 6147 | :param minvalue: the minimum value of the sequence. |
| 6148 | :param maxvalue: the maximum value of the sequence. |
| 6149 | :param nominvalue: no minimum value of the sequence. |
| 6150 | :param nomaxvalue: no maximum value of the sequence. |
| 6151 | :param cycle: allows the sequence to wrap around when the maxvalue |
| 6152 | or minvalue has been reached. |
| 6153 | :param cache: optional integer value; number of future values in the |
| 6154 | sequence which are calculated in advance. |
| 6155 | :param order: optional boolean value; if true, renders the |
| 6156 | ORDER keyword. |
| 6157 |