sqlalchemy.sql.expression.Update

Construct an _expression.Update object.

E.g.:

from sqlalchemy import update

stmt = (
    update(user_table).
    where(user_table.c.id == 5).
    values(name='user #5')
)

Similar functionality is available via the _expression.TableClause.update method on _schema.Table.

If both values and compile-time bind parameters are present, the compile-time bind parameters override the information specified within values on a per-key basis.

The keys within values can be either _schema.Column objects or their string identifiers (specifically the "key" of the _schema.Column, normally but not necessarily equivalent to its "name"). Normally, the _schema.Column objects used here are expected to be part of the target _schema.Table that is the table to be updated. However when using MySQL, a multiple-table UPDATE statement can refer to columns from any of the tables referred to in the WHERE clause.

The values referred to in values are typically:

• a literal data value (i.e. string, number, etc.)
• a SQL expression, such as a related _schema.Column, a scalar-returning _expression.select construct, etc.

When combining _expression.select constructs within the values clause of an _expression.update construct, the subquery represented by the _expression.select should be correlated to the parent table, that is, providing criterion which links the table inside the subquery to the outer table being updated:

users.update().values(
        name=select(addresses.c.email_address).\
                where(addresses.c.user_id==users.c.id).\
                scalar_subquery()
    )

Make this _expression.Update construct "inline" .

When set, SQL defaults present on _schema.Column objects via the default keyword will be compiled 'inline' into the statement and not pre-executed. This means that their values will not be available in the dictionary returned from _engine.CursorResult.last_updated_params.

Specify the VALUES clause of this UPDATE statement with an explicit parameter ordering that will be maintained in the SET clause of the resulting UPDATE statement.

E.g.:

stmt = table.update().ordered_values(
    ("name", "ed"), ("ident": "foo")
)