MapperProperty implementations.
This is a private module which defines the behavior of invidual ORM-mapped attributes.
Attached to a PropertyLoader to indicate a complementary reverse relationship.
Can optionally create the complementing PropertyLoader if one does not exist already.
Describes an object attribute that corresponds to a table column.
The list of columns describes a single object property. If there are multiple tables joined together for the mapper, this list represents the equivalent column as it appears across each table.
subclasses ColumnProperty to provide composite type support.
Describes an object property that holds a single item or list of items that correspond to a related database table.
Construct a new PropertyLoader.
return a join condition from the given parent mapper to this PropertyLoader's mapper.
The resulting ClauseElement object is cached and should not be modified directly.
- parent
- a mapper which has a relation() to this PropertyLoader. A PropertyLoader can have multiple "parents" when its actual parent mapper has inheriting mappers.
- primary
- include the primary join condition in the resulting join.
- secondary
- include the secondary join condition in the resulting join. If both primary and secondary are returned, they are joined via AND.
- polymorphic_parent
- if True, use the parent's 'select_table' instead of its 'mapped_table' to produce the join.