Class Func

django.db.models.expressions.Func

An SQL function call.

Declaration

class Func(SQLiteNumericMixin, Expression)

Documentation

Methods

▶ def __init__(self, *expressions, output_field=None, **extra) override
source link
This method overrides django.db.models.expressions.BaseExpression.__init__.
Overrides
This method is overriden in:
▷ def __repr__(self)
source link
▶ def as_sql(self, compiler, connection, function=None, template=None, arg_joiner=None, ...) override
inherited doc Responsible for returning a (sql, [params]) tuple to be included in the current query.
def as_sql(
self,
compiler,
connection,
function=None,
template=None,
arg_joiner=None,
**extra_context,
)
source link
This method overrides django.db.models.expressions.BaseExpression.as_sql.
```
Different backends can provide their own implementation, by
providing an `as_{vendor}` method and patching the Expression:

```
def override_as_sql(self, compiler, connection):
    # custom logic
    return super().as_sql(compiler, connection)
setattr(Expression, 'as_' + connection.vendor, override_as_sql)
```

Arguments:
 * compiler: the query compiler responsible for generating the query.
   Must have a compile method, returning a (sql, [params]) tuple.
   Calling compiler(value) will return a quoted `value`.

 * connection: the database connection used for the current query.

Return: (sql, params)
  Where `sql` is a string containing ordered sql parameters to be
  replaced with the elements of the list `params`.
```
Overrides
This method is overriden in:
▶ def copy(self) override
source link
This method overrides django.db.models.expressions.BaseExpression.copy.
▶ def get_source_expressions(self) override
source link
This method overrides django.db.models.expressions.BaseExpression.get_source_expressions.
Overrides
This method is overriden in:
- django.db.models.aggregates.Aggregate
▶ def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False) override
inherited doc Provide the chance to do any preprocessing or validation before being added to the query.
source link
This method overrides django.db.models.expressions.BaseExpression.resolve_expression.
```
Arguments:
 * query: the backend query implementation
 * allow_joins: boolean allowing or denying use of joins
   in this query
 * reuse: a set of reusable joins for multijoins
 * summarize: a terminal aggregate clause
 * for_save: whether this expression about to be used in a save or update

Return: an Expression to be added to the query.
```
Overrides
This method is overriden in:
▶ def set_source_expressions(self, exprs) override
source link
This method overrides django.db.models.expressions.BaseExpression.set_source_expressions.
Overrides
This method is overriden in:
- django.db.models.aggregates.Aggregate

Inherited methods

Methods inherited from django.db.models.expressions.SQLiteNumericMixin:
as_sqlite
Methods inherited from django.db.models.expressions.BaseExpression:
__eq__, __getstate__, __hash__, asc, conditional, contains_aggregate, contains_column_references, contains_over_clause, convert_value, desc, field, flatten, get_db_converters, get_group_by_cols, get_lookup, get_source_fields, get_transform, identity, output_field, relabeled_clone, reverse_ordering, select_format
Methods inherited from django.db.models.expressions.Combinable:
__add__, __and__, __mod__, __mul__, __neg__, __or__, __pow__, __radd__, __rand__, __rmod__, __rmul__, __ror__, __rpow__, __rsub__, __rtruediv__, __sub__, __truediv__, bitand, bitleftshift, bitor, bitrightshift, bitxor

Subclasses

Reexports

Imported in django.contrib.gis.db.backends.postgis.operations.
Imported in django.contrib.gis.db.models.functions.
Imported in django.contrib.postgres.functions.
Imported in django.contrib.postgres.search.
Imported in django.db.backends.oracle.functions.
Imported in django.db.models.lookups.
Imported in django.db.models.aggregates.
Imported in django.db.models.functions.window.
Imported in django.db.models.functions.comparison.
Imported in django.db.models.functions.math.
Imported in django.db.models.functions.text.
Imported in django.db.models.functions.datetime.
Imported in django.db.models.