diff options
| author | Mike Bayer <mike_mp@zzzcomputing.com> | 2019-12-16 17:06:43 -0500 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2020-07-03 23:39:51 -0400 |
| commit | 3dc9a4a2392d033f9d1bd79dd6b6ecea6281a61c (patch) | |
| tree | 1041bccb37422f526dccb5b1e57ffad1c702549b /lib/sqlalchemy/sql/expression.py | |
| parent | 5060043e8e95ab0aab5f63ed288c1426c46da66e (diff) | |
| download | sqlalchemy-3dc9a4a2392d033f9d1bd79dd6b6ecea6281a61c.tar.gz | |
introduce deferred lambdas
The coercions system allows us to add in lambdas as arguments
to Core and ORM elements without changing them at all. By allowing
the lambda to produce a deterministic cache key where we can also
cheat and yank out literal parameters means we can move towards
having 90% of "baked" functionality in a clearer way right in
Core / ORM.
As a second step, we can have whole statements inside the lambda,
and can then add generation with __add__(), so then we have
100% of "baked" functionality with full support of ad-hoc
literal values.
Adds some more short_selects tests for the moment for comparison.
Other tweaks inside cache key generation as we're trying to
approach a certain level of performance such that we can
remove the use of "baked" from the loader strategies.
As we have not yet closed #4639, however the caching feature
has been fully integrated as of
b0cfa7379cf8513a821a3dbe3028c4965d9f85bd, we will also
add complete caching documentation here and close that issue
as well.
Closes: #4639
Fixes: #5380
Change-Id: If91f61527236fd4d7ae3cad1f24c38be921c90ba
Diffstat (limited to 'lib/sqlalchemy/sql/expression.py')
| -rw-r--r-- | lib/sqlalchemy/sql/expression.py | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py index e25063372..37441a125 100644 --- a/lib/sqlalchemy/sql/expression.py +++ b/lib/sqlalchemy/sql/expression.py @@ -29,6 +29,8 @@ __all__ = [ "Insert", "Join", "Lateral", + "LambdaElement", + "StatementLambdaElement", "Select", "Selectable", "TableClause", @@ -59,6 +61,7 @@ __all__ = [ "join", "label", "lateral", + "lambda_stmt", "literal", "literal_column", "not_", @@ -135,6 +138,9 @@ from .functions import func # noqa from .functions import Function # noqa from .functions import FunctionElement # noqa from .functions import modifier # noqa +from .lambdas import lambda_stmt # noqa +from .lambdas import LambdaElement # noqa +from .lambdas import StatementLambdaElement # noqa from .selectable import Alias # noqa from .selectable import AliasedReturnsRows # noqa from .selectable import CompoundSelect # noqa |