Classe « MetaData »

Constructeur sqlalchemy.MetaData.__init__

Signature de la constructeur __init__

def __init__(self, bind=None, schema=None, quote_schema=None, naming_convention=None, info=None) 

Description

__init__.__doc__

Create a new MetaData object.

        :param bind:
          An Engine or Connection to bind to.  May also be a string or URL
          instance, these are passed to :func:`_sa.create_engine` and
          this :class:`_schema.MetaData` will
          be bound to the resulting engine.

          .. deprecated:: 1.4 The :paramref:`_schema.MetaData.bind` argument is deprecated and will be removed in SQLAlchemy 2.0.



        :param schema:
           The default schema to use for the :class:`_schema.Table`,
           :class:`.Sequence`, and potentially other objects associated with
           this :class:`_schema.MetaData`. Defaults to ``None``.

           .. seealso::

                :ref:`schema_metadata_schema_name` - details on how the
                :paramref:`_schema.MetaData.schema` parameter is used.

                :paramref:`_schema.Table.schema`

                :paramref:`.Sequence.schema`

        :param quote_schema:
            Sets the ``quote_schema`` flag for those :class:`_schema.Table`,
            :class:`.Sequence`, and other objects which make usage of the
            local ``schema`` name.

        :param info: Optional data dictionary which will be populated into the
            :attr:`.SchemaItem.info` attribute of this object.

            .. versionadded:: 1.0.0

        :param naming_convention: a dictionary referring to values which
          will establish default naming conventions for :class:`.Constraint`
          and :class:`.Index` objects, for those objects which are not given
          a name explicitly.

          The keys of this dictionary may be:

          * a constraint or Index class, e.g. the :class:`.UniqueConstraint`,
            :class:`_schema.ForeignKeyConstraint` class, the :class:`.Index`
            class

          * a string mnemonic for one of the known constraint classes;
            ``"fk"``, ``"pk"``, ``"ix"``, ``"ck"``, ``"uq"`` for foreign key,
            primary key, index, check, and unique constraint, respectively.

          * the string name of a user-defined "token" that can be used
            to define new naming tokens.

          The values associated with each "constraint class" or "constraint
          mnemonic" key are string naming templates, such as
          ``"uq_%(table_name)s_%(column_0_name)s"``,
          which describe how the name should be composed.  The values
          associated with user-defined "token" keys should be callables of the
          form ``fn(constraint, table)``, which accepts the constraint/index
          object and :class:`_schema.Table` as arguments, returning a string
          result.

          The built-in names are as follows, some of which may only be
          available for certain types of constraint:

            * ``%(table_name)s`` - the name of the :class:`_schema.Table`
              object
              associated with the constraint.

            * ``%(referred_table_name)s`` - the name of the
              :class:`_schema.Table`
              object associated with the referencing target of a
              :class:`_schema.ForeignKeyConstraint`.

            * ``%(column_0_name)s`` - the name of the :class:`_schema.Column`
              at
              index position "0" within the constraint.

            * ``%(column_0N_name)s`` - the name of all :class:`_schema.Column`
              objects in order within the constraint, joined without a
              separator.

            * ``%(column_0_N_name)s`` - the name of all
              :class:`_schema.Column`
              objects in order within the constraint, joined with an
              underscore as a separator.

            * ``%(column_0_label)s``, ``%(column_0N_label)s``,
              ``%(column_0_N_label)s`` - the label of either the zeroth
              :class:`_schema.Column` or all :class:`.Columns`, separated with
              or without an underscore

            * ``%(column_0_key)s``, ``%(column_0N_key)s``,
              ``%(column_0_N_key)s`` - the key of either the zeroth
              :class:`_schema.Column` or all :class:`.Columns`, separated with
              or without an underscore

            * ``%(referred_column_0_name)s``, ``%(referred_column_0N_name)s``
              ``%(referred_column_0_N_name)s``,  ``%(referred_column_0_key)s``,
              ``%(referred_column_0N_key)s``, ...  column tokens which
              render the names/keys/labels of columns that are referenced
              by a  :class:`_schema.ForeignKeyConstraint`.

            * ``%(constraint_name)s`` - a special key that refers to the
              existing name given to the constraint.  When this key is
              present, the :class:`.Constraint` object's existing name will be
              replaced with one that is composed from template string that
              uses this token. When this token is present, it is required that
              the :class:`.Constraint` is given an explicit name ahead of time.

            * user-defined: any additional token may be implemented by passing
              it along with a ``fn(constraint, table)`` callable to the
              naming_convention dictionary.

          .. versionadded:: 1.3.0 - added new ``%(column_0N_name)s``,
             ``%(column_0_N_name)s``, and related tokens that produce
             concatenations of names, keys, or labels for all columns referred
             to by a given constraint.

          .. seealso::

                :ref:`constraint_naming_conventions` - for detailed usage
                examples.