Release: 1.4.54 | Release Date: September 5, 2024

# SQLAlchemy 1.4 Documentation

# Insert, Updates, Deletes

INSERT, UPDATE and DELETE statements build on a hierarchy starting with `UpdateBase`. The `Insert` and `Update` constructs build on the intermediary `ValuesBase`.

## DML Foundational Constructors

Top level “INSERT”, “UPDATE”, “DELETE” constructors.

Object Name | Description
--- | ---
delete(table[, whereclause, bind, returning, ...], **dialect_kw) | Construct `Delete` object.
insert(table[, values, inline, bind, ...], **dialect_kw) | Construct an `Insert` object.
update(table[, whereclause, values, inline, ...], **dialect_kw) | Construct an `Update` object.

function sqlalchemy.sql.expression.delete(table, whereclause=None, bind=None, returning=None, prefixes=None, **dialect_kw)

  Construct `Delete` object.

  E.g.:

      from sqlalchemy import delete

      stmt = (
          delete(user_table).
          where(user_table.c.id == 5)
      )

  Similar functionality is available via the `TableClause.delete()` method on `Table`.

  See also

  Inserts, Updates and Deletes - in the 1.x tutorial

  Updating and Deleting Rows with Core - in the SQLAlchemy 1.4 / 2.0 Tutorial

  Parameters:

    - table – The table to delete rows from.

    - whereclause – Optional SQL expression describing the `WHERE` condition of the `DELETE` statement; is equivalent to using the more modern `Delete.where()` method to specify the `WHERE` clause.

  See also

  Deletes - SQL Expression Tutorial

function sqlalchemy.sql.expression.insert(table, values=None, inline=False, bind=None, prefixes=None, returning=None, return_defaults=False, **dialect_kw)

  Construct an `Insert` object.

  E.g.:

      from sqlalchemy import insert

      stmt = (
          insert(user_table).
          values(name='username', fullname='Full Username')
      )

  Similar functionality is available via the `TableClause.insert()` method on `Table`.

  See also

  Inserting Rows with Core - in the SQLAlchemy 1.4 / 2.0 Tutorial

  Parameters:

    - table – `TableClause` which is the subject of the insert.

    - values – collection of values to be inserted; see `Insert.values()` for a description of allowed formats here. Can be omitted entirely; a `Insert` construct will also dynamically render the VALUES clause at execution time based on the parameters passed to `Connection.execute()`.

    - inline – if True, no attempt will be made to retrieve the SQL-generated default values to be provided within the statement; in particular, this allows SQL expressions to be rendered ‘inline’ within the statement without the need to pre-execute them beforehand; for backends that support “returning”, this turns off the “implicit returning” feature for the statement.

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

  The keys within `Insert.values` can be either `Column` objects or their string identifiers. Each key may reference one of:

  - a literal data value (i.e. string, number, etc.);

  - a Column object;

  - a SELECT statement.

  If a `SELECT` statement is specified which references this `INSERT` statement’s table, the statement will be correlated against the `INSERT` statement.

  See also

  Inserting Rows with Core - in the SQLAlchemy 1.4 / 2.0 Tutorial

function sqlalchemy.sql.expression.update(table, whereclause=None, values=None, inline=False, bind=None, prefixes=None, returning=None, return_defaults=False, preserve_parameter_order=False, **dialect_kw)

  Construct an `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 `TableClause.update()` method on `Table`.

  Parameters:

    - table – A `Table` object representing the database table to be updated.

    - whereclause – Optional SQL expression describing the `WHERE` condition of the `UPDATE` statement; is equivalent to using the more modern `Update.where()` method to specify the `WHERE` clause.

    - values –

      Optional dictionary which specifies the `SET` conditions of the `UPDATE`. If left as `None`, the `SET` conditions are determined from those parameters passed to the statement during the execution and/or compilation of the statement. When compiled standalone without any parameters, the `SET` clause generates for all columns.

      Modern applications may prefer to use the generative `Update.values()` method to set the values of the UPDATE statement.

    - inline – if True, SQL defaults present on `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 `CursorResult.last_updated_params()`.

    - preserve_parameter_order –

      if True, the update statement is expected to receive parameters only via the `Update.values()` method, and they must be passed as a Python `list` of 2-tuples. The rendered UPDATE statement will emit the SET clause for each referenced column maintaining this order.

      Added in version 1.0.10.

      See also

      Parameter-Ordered Updates - illustrates the `Update.ordered_values()` method.

  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 `Column` objects or their string identifiers (specifically the “key” of the `Column`, normally but not necessarily equivalent to its “name”). Normally, the `Column` objects used here are expected to be part of the target `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 `Column`, a scalar-returning `select()` construct, etc.

  When combining `select()` constructs within the values clause of an `update()` construct, the subquery represented by the `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()
          )

  See also

  Inserts, Updates and Deletes - SQL Expression Language Tutorial

## DML Class Documentation Constructors

Class documentation for the constructors listed at DML Foundational Constructors.

Object Name | Description
--- | ---
Delete | Represent a DELETE construct.
Insert | Represent an INSERT construct.
Update | Represent an Update construct.
UpdateBase | Form the base for `INSERT`, `UPDATE`, and `DELETE` statements.
ValuesBase | Supplies support for `ValuesBase.values()` to INSERT and UPDATE constructs.

class sqlalchemy.sql.expression.Delete(table, whereclause=None, bind=None, returning=None, prefixes=None, **dialect_kw)

  Represent a DELETE construct.

  The `Delete` object is created using the `delete()` function.

  Members

  where(), returning(), __init__()

  Class signature

  class `sqlalchemy.sql.expression.Delete` (`sqlalchemy.sql.expression.DMLWhereBase`, `sqlalchemy.sql.expression.UpdateBase`)

  method `sqlalchemy.sql.expression.Delete.`where(*whereclause)

    inherited from the `DMLWhereBase.where()` method of `DMLWhereBase`

    Return a new construct with the given expression(s) added to its WHERE clause, joined to the existing clause via AND, if any.

    Both `Update.where()` and `Delete.where()` support multiple-table forms, including database-specific `UPDATE...FROM` as well as `DELETE..USING`. For backends that don’t have multiple-table support, a backend agnostic approach to using multiple tables is to make use of correlated subqueries. See the linked tutorial sections below for examples.

    See also

    Correlated Updates

    UPDATE..FROM

    Multiple Table Deletes

  method `sqlalchemy.sql.expression.Delete.`returning(*cols)

    inherited from the `UpdateBase.returning()` method of `UpdateBase`

    Add a RETURNING or equivalent clause to this statement.

    e.g.:

        >>> stmt = (
        ...     table.update()
        ...     .where(table.c.data == "value")
        ...     .values(status="X")
        ...     .returning(table.c.server_flag, table.c.updated_timestamp)
        ... )
        >>> print(stmt)
        UPDATE some_table SET status=:status
        WHERE some_table.data = :data_1
        RETURNING some_table.server_flag, some_table.updated_timestamp

    The method may be invoked multiple times to add new entries to the list of expressions to be returned.

    Added in version 1.4.0b2: The method may be invoked multiple times to add new entries to the list of expressions to be returned.

    The given collection of column expressions should be derived from the table that is the target of the INSERT, UPDATE, or DELETE. While `Column` objects are typical, the elements can also be expressions:

        >>> stmt = table.insert().returning(
        ...     (table.c.first_name + " " + table.c.last_name).label("fullname")
        ... )
        >>> print(stmt)
        INSERT INTO some_table (first_name, last_name)
        VALUES (:first_name, :last_name)
        RETURNING some_table.first_name || :first_name_1 || some_table.last_name AS fullname

    Upon compilation, a RETURNING clause, or database equivalent, will be rendered within the statement. For INSERT and UPDATE, the values are the newly inserted/updated values. For DELETE, the values are those of the rows which were deleted.

    Upon execution, the values of the columns to be returned are made available via the result set and can be iterated using `CursorResult.fetchone()` and similar. For DBAPIs which do not natively support returning values (i.e. cx_oracle), SQLAlchemy will approximate this behavior at the result level so that a reasonable amount of behavioral neutrality is provided.

    Note that not all databases/DBAPIs support RETURNING. For those backends with no support, an exception is raised upon compilation and/or execution. For those who do support it, the functionality across backends varies greatly, including restrictions on executemany() and other statements which return multiple rows. Please read the documentation notes for the database in use in order to determine the availability of RETURNING.

    See also

    `ValuesBase.return_defaults()` - an alternative method tailored towards efficient fetching of server-side defaults and triggers for single-row INSERTs or UPDATEs.

    INSERT…RETURNING - in the SQLAlchemy 1.4 / 2.0 Tutorial

  method `sqlalchemy.sql.expression.Delete.`__init__(table, whereclause=None, bind=None, returning=None, prefixes=None, **dialect_kw)

    Construct a new `Delete` object.

    This constructor is mirrored as a public API function; see `sqlalchemy.sql.expression.delete()` for a full usage and argument description.

class sqlalchemy.sql.expression.Insert(table, values=None, inline=False, bind=None, prefixes=None, returning=None, return_defaults=False, **dialect_kw)

  Represent an INSERT construct.

  The `Insert` object is created using the `insert()` function.

  Members

  values(), returning(), __init__(), from_select(), inline()

  Class signature

  class `sqlalchemy.sql.expression.Insert` (`sqlalchemy.sql.expression.ValuesBase`)

  method `sqlalchemy.sql.expression.Insert.`values(*args, **kwargs)

    inherited from the `ValuesBase.values()` method of `ValuesBase`

    Specify a fixed VALUES clause for an INSERT statement, or the SET clause for an UPDATE.

    Note that the `Insert` and `Update` constructs support per-execution time formatting of the VALUES and/or SET clauses, based on the arguments passed to `Connection.execute()`. However, the `ValuesBase.values()` method can be used to “fix” a particular set of parameters into the statement.

    Multiple calls to `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.

    Parameters:

      - **kwargs –

        key value pairs representing the string key of a `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")

      - *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 `Insert` or an `Update` construct.

        For either an `Insert` or `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 `Insert` construct, a tuple that contains an entry for every column in the table is also accepted:

            users.insert().values((5, "some name"))

        The `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 `Connection.execute()` method, which is supported by all database backends and is generally more efficient for a very large number of parameters.

        > > See also

        > > Sending Multiple Parameters - an introduction to the traditional Core method of multiple parameter set invocation for INSERTs and other statements.

        > > Changed in version 1.0.0: an INSERT that uses a multiple-VALUES clause, even a list of length one, implies that the `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 `CursorResult.inserted_primary_key` accessor does not apply.

        > > Changed in version 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 Python-side defaults invoked for each row individually when using a multivalued insert for other details.

        > The UPDATE construct also supports rendering the SET parameters in a specific order. For this feature refer to the `Update.ordered_values()` method.

        > > See also

        > > `Update.ordered_values()`

  method `sqlalchemy.sql.expression.Insert.`returning(*cols)

    inherited from the `UpdateBase.returning()` method of `UpdateBase`

    Add a RETURNING or equivalent clause to this statement.

    e.g.:

        >>> stmt = (
        ...     table.update()
        ...     .where(table.c.data == "value")
        ...     .values(status="X")
        ...     .returning(table.c.server_flag, table.c.updated_timestamp)
        ... )
        >>> print(stmt)
        UPDATE some_table SET status=:status
        WHERE some_table.data = :data_1
        RETURNING some_table.server_flag, some_table.updated_timestamp

    The method may be invoked multiple times to add new entries to the list of expressions to be returned.

    Added in version 1.4.0b2: The method may be invoked multiple times to add new entries to the list of expressions to be returned.

    The given collection of column expressions should be derived from the table that is the target of the INSERT, UPDATE, or DELETE. While `Column` objects are typical, the elements can also be expressions:

        >>> stmt = table.insert().returning(
        ...     (table.c.first_name + " " + table.c.last_name).label("fullname")
        ... )
        >>> print(stmt)
        INSERT INTO some_table (first_name, last_name)
        VALUES (:first_name, :last_name)
        RETURNING some_table.first_name || :first_name_1 || some_table.last_name AS fullname

    Upon compilation, a RETURNING clause, or database equivalent, will be rendered within the statement. For INSERT and UPDATE, the values are the newly inserted/updated values. For DELETE, the values are those of the rows which were deleted.

    Upon execution, the values of the columns to be returned are made available via the result set and can be iterated using `CursorResult.fetchone()` and similar. For DBAPIs which do not natively support returning values (i.e. cx_oracle), SQLAlchemy will approximate this behavior at the result level so that a reasonable amount of behavioral neutrality is provided.

    Note that not all databases/DBAPIs support RETURNING. For those backends with no support, an exception is raised upon compilation and/or execution. For those who do support it, the functionality across backends varies greatly, including restrictions on executemany() and other statements which return multiple rows. Please read the documentation notes for the database in use in order to determine the availability of RETURNING.

    See also

    `ValuesBase.return_defaults()` - an alternative method tailored towards efficient fetching of server-side defaults and triggers for single-row INSERTs or UPDATEs.

    INSERT…RETURNING - in the SQLAlchemy 1.4 / 2.0 Tutorial

  method `sqlalchemy.sql.expression.Insert.`__init__(table, values=None, inline=False, bind=None, prefixes=None, returning=None, return_defaults=False, **dialect_kw)

    Construct a new `Insert` object.

    This constructor is mirrored as a public API function; see `sqlalchemy.sql.expression.insert()` for a full usage and argument description.

  method `sqlalchemy.sql.expression.Insert.`from_select(names, select, include_defaults=True)

    Return a new `Insert` construct which represents an `INSERT...FROM SELECT` statement.

    e.g.:

        sel = select(table1.c.a, table1.c.b).where(table1.c.c > 5)
        ins = table2.insert().from_select(['a', 'b'], sel)

    Parameters:

      - names – a sequence of string column names or `Column` objects representing the target columns.

      - select – a `select()` construct, `FromClause` or other construct which resolves into a `FromClause`, such as an ORM `Query` object, etc. The order of columns returned from this FROM clause should correspond to the order of columns sent as the `names` parameter; while this is not checked before passing along to the database, the database would normally raise an exception if these column lists don’t correspond.

      - include_defaults –

        if True, non-server default values and SQL expressions as specified on `Column` objects (as documented in Column INSERT/UPDATE Defaults) not otherwise specified in the list of names will be rendered into the INSERT and SELECT statements, so that these values are also included in the data to be inserted.

        Note

        A Python-side default that uses a Python callable function will only be invoked once for the whole statement, and not per row.

        Added in version 1.0.0: - `Insert.from_select()` now renders Python-side and SQL expression column defaults into the SELECT statement for columns otherwise not included in the list of column names.

    Changed in version 1.0.0: an INSERT that uses FROM SELECT implies that the `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 `CursorResult.inserted_primary_key` accessor does not apply.

  method `sqlalchemy.sql.expression.Insert.`inline()

    Make this `Insert` construct “inline” .

    When set, no attempt will be made to retrieve the SQL-generated default values to be provided within the statement; in particular, this allows SQL expressions to be rendered ‘inline’ within the statement without the need to pre-execute them beforehand; for backends that support “returning”, this turns off the “implicit returning” feature for the statement.

    Changed in version 1.4: the `Insert.inline` parameter is now superseded by the `Insert.inline()` method.

class sqlalchemy.sql.expression.Update(table, whereclause=None, values=None, inline=False, bind=None, prefixes=None, returning=None, return_defaults=False, preserve_parameter_order=False, **dialect_kw)

  Represent an Update construct.

  The `Update` object is created using the `update()` function.

  Members

  returning(), where(), values(), __init__(), inline(), ordered_values()

  Class signature

  class `sqlalchemy.sql.expression.Update` (`sqlalchemy.sql.expression.DMLWhereBase`, `sqlalchemy.sql.expression.ValuesBase`)

  method `sqlalchemy.sql.expression.Update.`returning(*cols)

    inherited from the `UpdateBase.returning()` method of `UpdateBase`

    Add a RETURNING or equivalent clause to this statement.

    e.g.:

        >>> stmt = (
        ...     table.update()
        ...     .where(table.c.data == "value")
        ...     .values(status="X")
        ...     .returning(table.c.server_flag, table.c.updated_timestamp)
        ... )
        >>> print(stmt)
        UPDATE some_table SET status=:status
        WHERE some_table.data = :data_1
        RETURNING some_table.server_flag, some_table.updated_timestamp

    The method may be invoked multiple times to add new entries to the list of expressions to be returned.

    Added in version 1.4.0b2: The method may be invoked multiple times to add new entries to the list of expressions to be returned.

    The given collection of column expressions should be derived from the table that is the target of the INSERT, UPDATE, or DELETE. While `Column` objects are typical, the elements can also be expressions:

        >>> stmt = table.insert().returning(
        ...     (table.c.first_name + " " + table.c.last_name).label("fullname")
        ... )
        >>> print(stmt)
        INSERT INTO some_table (first_name, last_name)
        VALUES (:first_name, :last_name)
        RETURNING some_table.first_name || :first_name_1 || some_table.last_name AS fullname

    Upon compilation, a RETURNING clause, or database equivalent, will be rendered within the statement. For INSERT and UPDATE, the values are the newly inserted/updated values. For DELETE, the values are those of the rows which were deleted.

    Upon execution, the values of the columns to be returned are made available via the result set and can be iterated using `CursorResult.fetchone()` and similar. For DBAPIs which do not natively support returning values (i.e. cx_oracle), SQLAlchemy will approximate this behavior at the result level so that a reasonable amount of behavioral neutrality is provided.

    Note that not all databases/DBAPIs support RETURNING. For those backends with no support, an exception is raised upon compilation and/or execution. For those who do support it, the functionality across backends varies greatly, including restrictions on executemany() and other statements which return multiple rows. Please read the documentation notes for the database in use in order to determine the availability of RETURNING.

    See also

    `ValuesBase.return_defaults()` - an alternative method tailored towards efficient fetching of server-side defaults and triggers for single-row INSERTs or UPDATEs.

    INSERT…RETURNING - in the SQLAlchemy 1.4 / 2.0 Tutorial

  method `sqlalchemy.sql.expression.Update.`where(*whereclause)

    inherited from the `DMLWhereBase.where()` method of `DMLWhereBase`

    Return a new construct with the given expression(s) added to its WHERE clause, joined to the existing clause via AND, if any.

    Both `Update.where()` and `Delete.where()` support multiple-table forms, including database-specific `UPDATE...FROM` as well as `DELETE..USING`. For backends that don’t have multiple-table support, a backend agnostic approach to using multiple tables is to make use of correlated subqueries. See the linked tutorial sections below for examples.

    See also

    Correlated Updates

    UPDATE..FROM

    Multiple Table Deletes

  method `sqlalchemy.sql.expression.Update.`values(*args, **kwargs)

    inherited from the `ValuesBase.values()` method of `ValuesBase`

    Specify a fixed VALUES clause for an INSERT statement, or the SET clause for an UPDATE.

    Note that the `Insert` and `Update` constructs support per-execution time formatting of the VALUES and/or SET clauses, based on the arguments passed to `Connection.execute()`. However, the `ValuesBase.values()` method can be used to “fix” a particular set of parameters into the statement.

    Multiple calls to `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.

    Parameters:

      - **kwargs –

        key value pairs representing the string key of a `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")

      - *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 `Insert` or an `Update` construct.

        For either an `Insert` or `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 `Insert` construct, a tuple that contains an entry for every column in the table is also accepted:

            users.insert().values((5, "some name"))

        The `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 `Connection.execute()` method, which is supported by all database backends and is generally more efficient for a very large number of parameters.

        > > See also

        > > Sending Multiple Parameters - an introduction to the traditional Core method of multiple parameter set invocation for INSERTs and other statements.

        > > Changed in version 1.0.0: an INSERT that uses a multiple-VALUES clause, even a list of length one, implies that the `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 `CursorResult.inserted_primary_key` accessor does not apply.

        > > Changed in version 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 Python-side defaults invoked for each row individually when using a multivalued insert for other details.

        > The UPDATE construct also supports rendering the SET parameters in a specific order. For this feature refer to the `Update.ordered_values()` method.

        > > See also

        > > `Update.ordered_values()`

  method `sqlalchemy.sql.expression.Update.`__init__(table, whereclause=None, values=None, inline=False, bind=None, prefixes=None, returning=None, return_defaults=False, preserve_parameter_order=False, **dialect_kw)

    Construct a new `Update` object.

    This constructor is mirrored as a public API function; see `sqlalchemy.sql.expression.update()` for a full usage and argument description.

  method `sqlalchemy.sql.expression.Update.`inline()

    Make this `Update` construct “inline” .

    When set, SQL defaults present on `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 `CursorResult.last_updated_params()`.

    Changed in version 1.4: the `update.inline` parameter is now superseded by the `Update.inline()` method.

  method `sqlalchemy.sql.expression.Update.`ordered_values(*args)

    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")
        )

    See also

    Parameter Ordered Updates - full example of the `Update.ordered_values()` method.

    Changed in version 1.4: The `Update.ordered_values()` method supersedes the `update.preserve_parameter_order` parameter, which will be removed in SQLAlchemy 2.0.

class sqlalchemy.sql.expression.UpdateBase

  Form the base for `INSERT`, `UPDATE`, and `DELETE` statements.

  Members

  bind, entity_description, exported_columns, params(), returning(), returning_column_descriptions, with_dialect_options(), with_hint()

  Class signature

  class `sqlalchemy.sql.expression.UpdateBase` (`sqlalchemy.sql.roles.DMLRole`, `sqlalchemy.sql.expression.HasCTE`, `sqlalchemy.sql.expression.HasCompileState`, `sqlalchemy.sql.expression.DialectKWArgs`, `sqlalchemy.sql.expression.HasPrefixes`, `sqlalchemy.sql.expression.ReturnsRows`, `sqlalchemy.sql.expression.Executable`, `sqlalchemy.sql.expression.ClauseElement`)

  attribute `sqlalchemy.sql.expression.UpdateBase.`bind

    Return a ‘bind’ linked to this `UpdateBase` or a `Table` associated with it.

  attribute `sqlalchemy.sql.expression.UpdateBase.`entity_description

    Return a plugin-enabled description of the table and/or entity which this DML construct is operating against.

    This attribute is generally useful when using the ORM, as an extended structure which includes information about mapped entities is returned. The section Inspecting entities and columns from ORM-enabled SELECT and DML statements contains more background.

    For a Core statement, the structure returned by this accessor is derived from the `UpdateBase.table` attribute, and refers to the `Table` being inserted, updated, or deleted:

        >>> stmt = insert(user_table)
        >>> stmt.entity_description
        {
            "name": "user_table",
            "table": Table("user_table", ...)
        }

    Added in version 1.4.33.

    See also

    `UpdateBase.returning_column_descriptions`

    `Select.column_descriptions` - entity information for a `select()` construct

    Inspecting entities and columns from ORM-enabled SELECT and DML statements - ORM background

  attribute `sqlalchemy.sql.expression.UpdateBase.`exported_columns

    Return the RETURNING columns as a column collection for this statement.

    Added in version 1.4.

  method `sqlalchemy.sql.expression.UpdateBase.`params(*arg, **kw)

    Set the parameters for the statement.

    This method raises `NotImplementedError` on the base class, and is overridden by `ValuesBase` to provide the SET/VALUES clause of UPDATE and INSERT.

  method `sqlalchemy.sql.expression.UpdateBase.`returning(*cols)

    Add a RETURNING or equivalent clause to this statement.

    e.g.:

        >>> stmt = (
        ...     table.update()
        ...     .where(table.c.data == "value")
        ...     .values(status="X")
        ...     .returning(table.c.server_flag, table.c.updated_timestamp)
        ... )
        >>> print(stmt)
        UPDATE some_table SET status=:status
        WHERE some_table.data = :data_1
        RETURNING some_table.server_flag, some_table.updated_timestamp

    The method may be invoked multiple times to add new entries to the list of expressions to be returned.

    Added in version 1.4.0b2: The method may be invoked multiple times to add new entries to the list of expressions to be returned.

    The given collection of column expressions should be derived from the table that is the target of the INSERT, UPDATE, or DELETE. While `Column` objects are typical, the elements can also be expressions:

        >>> stmt = table.insert().returning(
        ...     (table.c.first_name + " " + table.c.last_name).label("fullname")
        ... )
        >>> print(stmt)
        INSERT INTO some_table (first_name, last_name)
        VALUES (:first_name, :last_name)
        RETURNING some_table.first_name || :first_name_1 || some_table.last_name AS fullname

    Upon compilation, a RETURNING clause, or database equivalent, will be rendered within the statement. For INSERT and UPDATE, the values are the newly inserted/updated values. For DELETE, the values are those of the rows which were deleted.

    Upon execution, the values of the columns to be returned are made available via the result set and can be iterated using `CursorResult.fetchone()` and similar. For DBAPIs which do not natively support returning values (i.e. cx_oracle), SQLAlchemy will approximate this behavior at the result level so that a reasonable amount of behavioral neutrality is provided.

    Note that not all databases/DBAPIs support RETURNING. For those backends with no support, an exception is raised upon compilation and/or execution. For those who do support it, the functionality across backends varies greatly, including restrictions on executemany() and other statements which return multiple rows. Please read the documentation notes for the database in use in order to determine the availability of RETURNING.

    See also

    `ValuesBase.return_defaults()` - an alternative method tailored towards efficient fetching of server-side defaults and triggers for single-row INSERTs or UPDATEs.

    INSERT…RETURNING - in the SQLAlchemy 1.4 / 2.0 Tutorial

  attribute `sqlalchemy.sql.expression.UpdateBase.`returning_column_descriptions

    Return a plugin-enabled description of the columns which this DML construct is RETURNING against, in other words the expressions established as part of `UpdateBase.returning()`.

    This attribute is generally useful when using the ORM, as an extended structure which includes information about mapped entities is returned. The section Inspecting entities and columns from ORM-enabled SELECT and DML statements contains more background.

    For a Core statement, the structure returned by this accessor is derived from the same objects that are returned by the `UpdateBase.exported_columns` accessor:

        >>> stmt = insert(user_table).returning(user_table.c.id, user_table.c.name)
        >>> stmt.entity_description
        [
            {
                "name": "id",
                "type": Integer,
                "expr": Column("id", Integer(), table=<user>, ...)
            },
            {
                "name": "name",
                "type": String(),
                "expr": Column("name", String(), table=<user>, ...)
            },
        ]

    Added in version 1.4.33.

    See also

    `UpdateBase.entity_description`

    `Select.column_descriptions` - entity information for a `select()` construct

    Inspecting entities and columns from ORM-enabled SELECT and DML statements - ORM background

  method `sqlalchemy.sql.expression.UpdateBase.`with_dialect_options(**opt)

    Add dialect options to this INSERT/UPDATE/DELETE object.

    e.g.:

        upd = table.update().dialect_options(mysql_limit=10)

  method `sqlalchemy.sql.expression.UpdateBase.`with_hint(text, selectable=None, dialect_name='*')

    Add a table hint for a single table to this INSERT/UPDATE/DELETE statement.

    Note

    `UpdateBase.with_hint()` currently applies only to Microsoft SQL Server. For MySQL INSERT/UPDATE/DELETE hints, use `UpdateBase.prefix_with()`.

    The text of the hint is rendered in the appropriate location for the database backend in use, relative to the `Table` that is the subject of this statement, or optionally to that of the given `Table` passed as the `selectable` argument.

    The `dialect_name` option will limit the rendering of a particular hint to a particular backend. Such as, to add a hint that only takes effect for SQL Server:

        mytable.insert().with_hint("WITH (PAGLOCK)", dialect_name="mssql")

    Parameters:

      - text – Text of the hint.

      - selectable – optional `Table` that specifies an element of the FROM clause within an UPDATE or DELETE to be the subject of the hint - applies only to certain backends.

      - dialect_name – defaults to `*`, if specified as the name of a particular dialect, will apply these hints only when that dialect is in use.

class sqlalchemy.sql.expression.ValuesBase(table, values, prefixes)

  Supplies support for `ValuesBase.values()` to INSERT and UPDATE constructs.

  Members

  return_defaults(), values()

  Class signature

  class `sqlalchemy.sql.expression.ValuesBase` (`sqlalchemy.sql.expression.UpdateBase`)

  method `sqlalchemy.sql.expression.ValuesBase.`return_defaults(*cols)

    Make use of a RETURNING clause for the purpose of fetching server-side expressions and defaults.

    E.g.:

        stmt = table.insert().values(data='newdata').return_defaults()

        result = connection.execute(stmt)

        server_created_at = result.returned_defaults['created_at']

    When used against a backend that supports RETURNING, all column values generated by SQL expression or server-side-default will be added to any existing RETURNING clause, provided that `UpdateBase.returning()` is not used simultaneously. The column values will then be available on the result using the `CursorResult.returned_defaults` accessor as a dictionary, referring to values keyed to the `Column` object as well as its `.key`.

    This method differs from `UpdateBase.returning()` in these ways:

    1. `ValuesBase.return_defaults()` is only intended for use with an INSERT or an UPDATE statement that matches exactly one row per parameter set. While the RETURNING construct in the general sense supports multiple rows for a multi-row UPDATE or DELETE statement, or for special cases of INSERT that return multiple rows (e.g. INSERT from SELECT, multi-valued VALUES clause), `ValuesBase.return_defaults()` is intended only for an “ORM-style” single-row INSERT/UPDATE statement. The row returned by the statement is also consumed implicitly when `ValuesBase.return_defaults()` is used. By contrast, `UpdateBase.returning()` leaves the RETURNING result-set intact with a collection of any number of rows.

    2. It is compatible with the existing logic to fetch auto-generated primary key values, also known as “implicit returning”. Backends that support RETURNING will automatically make use of RETURNING in order to fetch the value of newly generated primary keys; while the `UpdateBase.returning()` method circumvents this behavior, `ValuesBase.return_defaults()` leaves it intact.

    3. It can be called against any backend. Backends that don’t support RETURNING will skip the usage of the feature, rather than raising an exception. The return value of `CursorResult.returned_defaults` will be `None`

    4. An INSERT statement invoked with executemany() is supported if the backend database driver supports the `insert_executemany_returning` feature, currently this includes PostgreSQL with psycopg2. When executemany is used, the `CursorResult.returned_defaults_rows` and `CursorResult.inserted_primary_key_rows` accessors will return the inserted defaults and primary keys.

       Added in version 1.4.

    `ValuesBase.return_defaults()` is used by the ORM to provide an efficient implementation for the `eager_defaults` feature of `mapper()`.

    Parameters:

      cols – optional list of column key names or `Column` objects. If omitted, all column expressions evaluated on the server are added to the returning list.

    Added in version 0.9.0.

    See also

    `UpdateBase.returning()`

    `CursorResult.returned_defaults`

    `CursorResult.returned_defaults_rows`

    `CursorResult.inserted_primary_key`

    `CursorResult.inserted_primary_key_rows`

  method `sqlalchemy.sql.expression.ValuesBase.`values(*args, **kwargs)

    Specify a fixed VALUES clause for an INSERT statement, or the SET clause for an UPDATE.

    Note that the `Insert` and `Update` constructs support per-execution time formatting of the VALUES and/or SET clauses, based on the arguments passed to `Connection.execute()`. However, the `ValuesBase.values()` method can be used to “fix” a particular set of parameters into the statement.

    Multiple calls to `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.

    Parameters:

      - **kwargs –

        key value pairs representing the string key of a `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")

      - *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 `Insert` or an `Update` construct.

        For either an `Insert` or `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 `Insert` construct, a tuple that contains an entry for every column in the table is also accepted:

            users.insert().values((5, "some name"))

        The `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 `Connection.execute()` method, which is supported by all database backends and is generally more efficient for a very large number of parameters.

        > > See also

        > > Sending Multiple Parameters - an introduction to the traditional Core method of multiple parameter set invocation for INSERTs and other statements.

        > > Changed in version 1.0.0: an INSERT that uses a multiple-VALUES clause, even a list of length one, implies that the `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 `CursorResult.inserted_primary_key` accessor does not apply.

        > > Changed in version 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 Python-side defaults invoked for each row individually when using a multivalued insert for other details.

        > The UPDATE construct also supports rendering the SET parameters in a specific order. For this feature refer to the `Update.ordered_values()` method.

        > > See also

        > > `Update.ordered_values()`