Class WhereNode
An SQL WHERE clause.
Declaration
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The class is tied to the Query class that created it (in order to create
the correct SQL).
A child is usually an expression producing boolean values. Most likely the
expression is a Lookup instance.
However, a child could also be any class with as_sql() and either
relabeled_clone() method or relabel_aliases() and clone() methods and
contains_aggregate attribute.
Methods
▶ def as_sql(self, compiler, connection) Return the SQL version of the where clause and the value to be
substituted in. Return '', [] if this node matches everything,
None, [] if this node is empty, and raise EmptyResultSet if this
node can't match anything.
▷ def clone(self) Create a clone of the tree. Must only be called on root nodes (nodes with empty subtree_parents). Childs must be either (Constraint, lookup, value) tuples, or objects supporting .clone().
@cached_property
def contains_aggregate(self)
@cached_property
def contains_over_clause(self)
@property
def is_summary(self)
▷ def relabel_aliases(self, change_map) Relabel the alias values of any children. 'change_map' is a dictionary mapping old (current) alias values to the new values.
▷ def split_having(self, negated=False) Return two possibly None nodes: one for those parts of self that should be included in the WHERE clause and one for those parts of self that must be included in the HAVING clause.