pir_pipeline.utils.sql_alchemy_view.DropView

class pir_pipeline.utils.sql_alchemy_view.DropView(name)

Bases: ExecutableDDLElement

Class for dropping a view

__init__(name)

Methods

__init__(name)
against(target)	Return a copy of this _schema.ExecutableDDLElement which will include the given target.
compare(other, **kw)	Compare this _expression.ClauseElement to the given _expression.ClauseElement.
compile([bind, dialect])	Compile this SQL expression.
execute_if([dialect, callable_, state])	Return a callable that will execute this _ddl.ExecutableDDLElement conditionally within an event handler.
execution_options(**kw)	Set non-SQL options for the statement which take effect during execution.
get_children(*[, omit_attrs])	Return immediate child visitors.HasTraverseInternals elements of this visitors.HasTraverseInternals.
get_execution_options()	Get the non-SQL options which will take effect during execution.
memoized_instancemethod(fn)	Decorate a method memoize its return value.
options(*options)	Apply options to this statement.
params([_ClauseElement__optionaldict])	Return a copy with _expression.bindparam() elements replaced.
self_group([against])	Apply a 'grouping' to this _expression.ClauseElement.
unique_params([_ClauseElement__optionaldict])	Return a copy with _expression.bindparam() elements replaced.

Attributes

allows_lambda
description
entity_namespace
inherit_cache	Indicate if this HasCacheKey instance should make use of the cache key generation scheme used by its immediate superclass.
is_clause_element
is_delete
is_dml
is_from_statement
is_insert
is_select
is_selectable
is_text
is_update
stringify_dialect
supports_execution
target
uses_inspection
negation_clause
proxy_set

against(target: SchemaItem) → Self

Return a copy of this _schema.ExecutableDDLElement which will include the given target.

This essentially applies the given item to the .target attribute of the returned _schema.ExecutableDDLElement object. This target is then usable by event handlers and compilation routines in order to provide services such as tokenization of a DDL string in terms of a particular _schema.Table.

When a _schema.ExecutableDDLElement object is established as an event handler for the _events.DDLEvents.before_create() or _events.DDLEvents.after_create() events, and the event then occurs for a given target such as a _schema.Constraint or _schema.Table, that target is established with a copy of the _schema.ExecutableDDLElement object using this method, which then proceeds to the _schema.ExecutableDDLElement.execute() method in order to invoke the actual DDL instruction.

Parameters:

target – a _schema.SchemaItem that will be the subject of a DDL operation.

Returns:

a copy of this _schema.ExecutableDDLElement with the .target attribute assigned to the given _schema.SchemaItem.

See also

_schema.DDL - uses tokenization against the “target” when processing the DDL string.

compare(other: ClauseElement, **kw: Any) → bool

Compare this _expression.ClauseElement to the given _expression.ClauseElement.

Subclasses should override the default behavior, which is a straight identity comparison.

**kw are arguments consumed by subclass compare() methods and may be used to modify the criteria for comparison (see _expression.ColumnElement).

compile(bind: _HasDialect | None = None, dialect: Dialect | None = None, **kw: Any) → Compiled

Compile this SQL expression.

The return value is a Compiled object. Calling str() or unicode() on the returned value will yield a string representation of the result. The Compiled object also can return a dictionary of bind parameter names and values using the params accessor.

Parameters:

• bind – An Connection or Engine which can provide a Dialect in order to generate a Compiled object. If the bind and dialect parameters are both omitted, a default SQL compiler is used.

• column_keys – Used for INSERT and UPDATE statements, a list of column names which should be present in the VALUES clause of the compiled statement. If None, all columns from the target table object are rendered.

• dialect – A Dialect instance which can generate a Compiled object. This argument takes precedence over the bind argument.

• compile_kwargs –

  optional dictionary of additional parameters that will be passed through to the compiler within all “visit” methods. This allows any custom flag to be passed through to a custom compilation construct, for example. It is also used for the case of passing the literal_binds flag through:

  from sqlalchemy.sql import table, column, select
  
  t = table("t", column("x"))
  
  s = select(t).where(t.c.x == 5)
  
  print(s.compile(compile_kwargs={"literal_binds": True}))
  

See also

faq_sql_expression_string

execute_if(dialect: str | None = None, callable_: DDLIfCallable | None = None, state: Any | None = None) → Self

Return a callable that will execute this _ddl.ExecutableDDLElement conditionally within an event handler.

Used to provide a wrapper for event listening:

event.listen(
    metadata,
    "before_create",
    DDL("my_ddl").execute_if(dialect="postgresql"),
)

Parameters:

• dialect –

  May be a string or tuple of strings. If a string, it will be compared to the name of the executing database dialect:

  DDL("something").execute_if(dialect="postgresql")
  

  If a tuple, specifies multiple dialect names:

  DDL("something").execute_if(dialect=("postgresql", "mysql"))
  

• callable_ –

  A callable, which will be invoked with three positional arguments as well as optional keyword arguments:

  ddl:

  This DDL element.

  target:

  The _schema.Table or _schema.MetaData object which is the target of this event. May be None if the DDL is executed explicitly.

  bind:

  The _engine.Connection being used for DDL execution. May be None if this construct is being created inline within a table, in which case compiler will be present.

  tables:

  Optional keyword argument - a list of Table objects which are to be created/ dropped within a MetaData.create_all() or drop_all() method call.

  dialect:

  keyword argument, but always present - the Dialect involved in the operation.

  compiler:

  keyword argument. Will be None for an engine level DDL invocation, but will refer to a DDLCompiler if this DDL element is being created inline within a table.

  state:

  Optional keyword argument - will be the state argument passed to this function.

  checkfirst:

  Keyword argument, will be True if the ‘checkfirst’ flag was set during the call to create(), create_all(), drop(), drop_all().

  If the callable returns a True value, the DDL statement will be executed.

• state – any value which will be passed to the callable_ as the state keyword argument.

See also

SchemaItem.ddl_if()

DDLEvents

event_toplevel

execution_options(**kw: Any) → Self

Set non-SQL options for the statement which take effect during execution.

Execution options can be set at many scopes, including per-statement, per-connection, or per execution, using methods such as _engine.Connection.execution_options() and parameters which accept a dictionary of options such as :paramref:`_engine.Connection.execute.execution_options` and :paramref:`_orm.Session.execute.execution_options`.

The primary characteristic of an execution option, as opposed to other kinds of options such as ORM loader options, is that execution options never affect the compiled SQL of a query, only things that affect how the SQL statement itself is invoked or how results are fetched. That is, execution options are not part of what’s accommodated by SQL compilation nor are they considered part of the cached state of a statement.

The _sql.Executable.execution_options() method is generative, as is the case for the method as applied to the _engine.Engine and _orm.Query objects, which means when the method is called, a copy of the object is returned, which applies the given parameters to that new copy, but leaves the original unchanged:

statement = select(table.c.x, table.c.y)
new_statement = statement.execution_options(my_option=True)

An exception to this behavior is the _engine.Connection object, where the _engine.Connection.execution_options() method is explicitly not generative.

The kinds of options that may be passed to _sql.Executable.execution_options() and other related methods and parameter dictionaries include parameters that are explicitly consumed by SQLAlchemy Core or ORM, as well as arbitrary keyword arguments not defined by SQLAlchemy, which means the methods and/or parameter dictionaries may be used for user-defined parameters that interact with custom code, which may access the parameters using methods such as _sql.Executable.get_execution_options() and _engine.Connection.get_execution_options(), or within selected event hooks using a dedicated execution_options event parameter such as :paramref:`_events.ConnectionEvents.before_execute.execution_options` or _orm.ORMExecuteState.execution_options, e.g.:

from sqlalchemy import event


@event.listens_for(some_engine, "before_execute")
def _process_opt(conn, statement, multiparams, params, execution_options):
    "run a SQL function before invoking a statement"

    if execution_options.get("do_special_thing", False):
        conn.exec_driver_sql("run_special_function()")

Within the scope of options that are explicitly recognized by SQLAlchemy, most apply to specific classes of objects and not others. The most common execution options include:

• :paramref:`_engine.Connection.execution_options.isolation_level` - sets the isolation level for a connection or a class of connections via an _engine.Engine. This option is accepted only by _engine.Connection or _engine.Engine.

• :paramref:`_engine.Connection.execution_options.stream_results` - indicates results should be fetched using a server side cursor; this option is accepted by _engine.Connection, by the :paramref:`_engine.Connection.execute.execution_options` parameter on _engine.Connection.execute(), and additionally by _sql.Executable.execution_options() on a SQL statement object, as well as by ORM constructs like _orm.Session.execute().

• :paramref:`_engine.Connection.execution_options.compiled_cache` - indicates a dictionary that will serve as the SQL compilation cache for a _engine.Connection or _engine.Engine, as well as for ORM methods like _orm.Session.execute(). Can be passed as None to disable caching for statements. This option is not accepted by _sql.Executable.execution_options() as it is inadvisable to carry along a compilation cache within a statement object.

• :paramref:`_engine.Connection.execution_options.schema_translate_map` - a mapping of schema names used by the Schema Translate Map feature, accepted by _engine.Connection, _engine.Engine, _sql.Executable, as well as by ORM constructs like _orm.Session.execute().

See also

_engine.Connection.execution_options()

:paramref:`_engine.Connection.execute.execution_options`

:paramref:`_orm.Session.execute.execution_options`

orm_queryguide_execution_options - documentation on all ORM-specific execution options

get_children(*, omit_attrs: Tuple[str, ...] = (), **kw: Any) → Iterable[HasTraverseInternals]

Return immediate child visitors.HasTraverseInternals elements of this visitors.HasTraverseInternals.

This is used for visit traversal.

**kw may contain flags that change the collection that is returned, for example to return a subset of items in order to cut down on larger traversals, or to return child items from a different context (such as schema-level collections instead of clause-level).

get_execution_options() → _ExecuteOptions

Get the non-SQL options which will take effect during execution.

Added in version 1.3.

See also

Executable.execution_options()

inherit_cache: bool | None = None

Indicate if this HasCacheKey instance should make use of the cache key generation scheme used by its immediate superclass.

The attribute defaults to None, which indicates that a construct has not yet taken into account whether or not its appropriate for it to participate in caching; this is functionally equivalent to setting the value to False, except that a warning is also emitted.

This flag can be set to True on a particular class, if the SQL that corresponds to the object does not change based on attributes which are local to this class, and not its superclass.

See also

compilerext_caching - General guideslines for setting the HasCacheKey.inherit_cache attribute for third-party or user defined SQL constructs.

options(*options: ExecutableOption) → Self

Apply options to this statement.

In the general sense, options are any kind of Python object that can be interpreted by the SQL compiler for the statement. These options can be consumed by specific dialects or specific kinds of compilers.

The most commonly known kind of option are the ORM level options that apply “eager load” and other loading behaviors to an ORM query. However, options can theoretically be used for many other purposes.

For background on specific kinds of options for specific kinds of statements, refer to the documentation for those option objects.

Changed in version 1.4: - added Executable.options() to Core statement objects towards the goal of allowing unified Core / ORM querying capabilities.

See also

loading_columns - refers to options specific to the usage of ORM queries

relationship_loader_options - refers to options specific to the usage of ORM queries

params(_ClauseElement__optionaldict: Mapping[str, Any] | None = None, **kwargs: Any) → Self

Return a copy with _expression.bindparam() elements replaced.

Returns a copy of this ClauseElement with _expression.bindparam() elements replaced with values taken from the given dictionary:

>>> clause = column("x") + bindparam("foo")
>>> print(clause.compile().params)
{'foo':None}
>>> print(clause.params({"foo": 7}).compile().params)
{'foo':7}

self_group(against: OperatorType | None = None) → ClauseElement

Apply a ‘grouping’ to this _expression.ClauseElement.

This method is overridden by subclasses to return a “grouping” construct, i.e. parenthesis. In particular it’s used by “binary” expressions to provide a grouping around themselves when placed into a larger expression, as well as by _expression.select() constructs when placed into the FROM clause of another _expression.select(). (Note that subqueries should be normally created using the _expression.Select.alias() method, as many platforms require nested SELECT statements to be named).

As expressions are composed together, the application of self_group() is automatic - end-user code should never need to use this method directly. Note that SQLAlchemy’s clause constructs take operator precedence into account - so parenthesis might not be needed, for example, in an expression like x OR (y AND z) - AND takes precedence over OR.

The base self_group() method of _expression.ClauseElement just returns self.

unique_params(_ClauseElement__optionaldict: Dict[str, Any] | None = None, **kwargs: Any) → Self

Return a copy with _expression.bindparam() elements replaced.

Same functionality as _expression.ClauseElement.params(), except adds unique=True to affected bind parameters so that multiple statements can be used.