Model index referenceLink para este cabeçalho
Index classes ease creating database indexes. They can be added using the
Meta.indexes option. This document
explains the API references of Index which includes the index
options.
Index optionsLink para este cabeçalho
- class Index(fields=(), name=None, db_tablespace=None, opclasses=(), condition=None)Link para esta definição
Creates an index (B-Tree) in the database.
fieldsLink para este cabeçalho
- Index.fieldsLink para esta definição
A list or tuple of the name of the fields on which the index is desired.
By default, indexes are created with an ascending order for each column. To define an index with a descending order for a column, add a hyphen before the field’s name.
For example Index(fields=['headline', '-pub_date']) would create SQL with
(headline, pub_date DESC). Index ordering isn’t supported on MySQL. In that
case, a descending index is created as a normal index.
nameLink para este cabeçalho
- Index.nameLink para esta definição
The name of the index. If name isn’t provided Django will auto-generate a
name. For compatibility with different databases, index names cannot be longer
than 30 characters and shouldn’t start with a number (0-9) or underscore (_).
db_tablespaceLink para este cabeçalho
- Index.db_tablespaceLink para esta definição
The name of the database tablespace to use for
this index. For single field indexes, if db_tablespace isn’t provided, the
index is created in the db_tablespace of the field.
If Field.db_tablespace isn’t specified (or if the index uses multiple
fields), the index is created in tablespace specified in the
db_tablespace option inside the model’s
class Meta. If neither of those tablespaces are set, the index is created
in the same tablespace as the table.
opclassesLink para este cabeçalho
- Index.opclassesLink para esta definição
The names of the PostgreSQL operator classes to use for this index. If you require a custom operator class, you must provide one for each field in the index.
For example, GinIndex(name='json_index', fields=['jsonfield'],
opclasses=['jsonb_path_ops']) creates a gin index on jsonfield using
jsonb_path_ops.
opclasses are ignored for databases besides PostgreSQL.
Index.name is required when using opclasses.
conditionLink para este cabeçalho
- Index.conditionLink para esta definição
If the table is very large and your queries mostly target a subset of rows,
it may be useful to restrict an index to that subset. Specify a condition as a
Q. For example, condition=Q(pages__gt=400)
indexes records with more than 400 pages.
Index.name is required when using condition.