Class Query

django/db/models/sql/query.py:231–2791

A single SQL query.

class Query(BaseExpression):
    """A single SQL query."""

    alias_prefix = "T"
    empty_result_set_value = None
    subq_aliases = frozenset([alias_prefix])

    compiler = "SQLCompiler"

    base_table_class = BaseTable
    join_class = Join

    default_cols = True
    default_ordering = True
    standard_ordering = True

    filter_is_sticky = False
    subquery = False
    contains_subquery = False

    # SQL-related attributes.
    # Select and related select clauses are expressions to use in the SELECT
    # clause of the query. The select is used for cases where we want to set up
    # the select clause to contain other than default fields (values(),
    # subqueries...). Note that annotations go to annotations dictionary.
    select = ()
    # The group_by attribute can have one of the following forms:
    #  - None: no group by at all in the query
    #  - A tuple of expressions: group by (at least) those expressions.
    #    String refs are also allowed for now.
    #  - True: group by all select fields of the model
    # See compiler.get_group_by() for details.
    group_by = None
    order_by = ()
    low_mark = 0  # Used for offset/limit.
    high_mark = None  # Used for offset/limit.
    distinct = False
    distinct_fields = ()
    select_for_update = False
    select_for_update_nowait = False
    select_for_update_skip_locked = False
    select_for_update_of = ()
    select_for_no_key_update = False
    select_related = False
    # Arbitrary limit for select_related to prevents infinite recursion.
    max_depth = 5
    # Holds the selects defined by a call to values() or values_list()
    # excluding annotation_select and extra_select.
    values_select = ()
    selected = None

    # SQL annotation-related attributes.
    annotation_select_mask = None
    _annotation_select_cache = None

    # Set combination attributes.
    combinator = None
    combinator_all = False