sqlalchemy.sql.dml.ValuesBase

Undocumented

Specify a fixed VALUES clause for an INSERT statement, or the SET clause for an UPDATE. Note that the :class:`_expression.Insert` and :class:`_expression.Update` constructs support per-execution time formatting of the VALUES and/or SET clauses, based on the arguments passed to :meth:`_engine.Connection.execute`. However, the :meth:`.ValuesBase.values` method can be used to "fix" a particular set of parameters into the statement. Multiple calls to :meth:`.ValuesBase.values` will produce a new construct, each one with the parameter list modified to include the new parameters sent. In the typical case of a single dictionary of parameters, the newly passed keys will replace the same keys in the previous construct. In the case of a list-based "multiple values" construct, each new list of values is extended onto the existing list of values. :param \**kwargs: key value pairs representing the string key of a :class:`_schema.Column` mapped to the value to be rendered into the VALUES or SET clause:: users.insert().values(name="some name") users.update().where(users.c.id==5).values(name="some name") :param \*args: As an alternative to passing key/value parameters, a dictionary, tuple, or list of dictionaries or tuples can be passed as a single positional argument in order to form the VALUES or SET clause of the statement. The forms that are accepted vary based on whether this is an :class:`_expression.Insert` or an :class:`_expression.Update` construct. For either an :class:`_expression.Insert` or :class:`_expression.Update` construct, a single dictionary can be passed, which works the same as that of the kwargs form:: users.insert().values({"name": "some name"}) users.update().values({"name": "some new name"}) Also for either form but more typically for the :class:`_expression.Insert` construct, a tuple that contains an entry for every column in the table is also accepted:: users.insert().values((5, "some name")) The :class:`_expression.Insert` construct also supports being passed a list of dictionaries or full-table-tuples, which on the server will render the less common SQL syntax of "multiple values" - this syntax is supported on backends such as SQLite, PostgreSQL, MySQL, but not necessarily others:: users.insert().values([ {"name": "some name"}, {"name": "some other name"}, {"name": "yet another name"}, ]) The above form would render a multiple VALUES statement similar to:: INSERT INTO users (name) VALUES (:name_1), (:name_2), (:name_3) It is essential to note that **passing multiple values is NOT the same as using traditional executemany() form**. The above syntax is a **special** syntax not typically used. To emit an INSERT statement against multiple rows, the normal method is to pass a multiple values list to the :meth:`_engine.Connection.execute` method, which is supported by all database backends and is generally more efficient for a very large number of parameters. .. seealso:: :ref:`tutorial_multiple_parameters` - an introduction to the traditional Core method of multiple parameter set invocation for INSERTs and other statements. .. versionchanged:: 1.0.0 an INSERT that uses a multiple-VALUES clause, even a list of length one, implies that the :paramref:`_expression.Insert.inline` flag is set to True, indicating that the statement will not attempt to fetch the "last inserted primary key" or other defaults. The statement deals with an arbitrary number of rows, so the :attr:`_engine.CursorResult.inserted_primary_key` accessor does not apply. .. versionchanged:: 1.0.0 A multiple-VALUES INSERT now supports columns with Python side default values and callables in the same way as that of an "executemany" style of invocation; the callable is invoked for each row. See :ref:`bug_3288` for other details. The UPDATE construct also supports rendering the SET parameters in a specific order. For this feature refer to the :meth:`_expression.Update.ordered_values` method. .. seealso:: :meth:`_expression.Update.ordered_values`