org.apache.ignite.cache.query.annotations

Annotation Type QuerySqlField.Group

@Retention(value=RUNTIME)
 @Target(value={METHOD,FIELD})
public static @interface QuerySqlField.Group

Describes group of index and position of field in this group.

Opposite to QuerySqlField.groups() this annotation gives control over order of fields in a group index. This can be needed in scenarios when we have a query like select * from X where a = ? and b = ? order by b desc. If we have index (a asc, b asc) sorting on b will be performed. Here it is preferable to have index (b desc, a asc) which will still allow query to search on index using both fields and avoid sorting because index is already sorted in needed way.

See Also:

QuerySqlField.groups(), QuerySqlField.orderedGroups()

Required Element Summary

Required Elements

Modifier and Type	Required Element and Description
String	name Group index name where this field participate.
int	order Fields in this group index will be sorted on this attribute.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
boolean	descending Defines sorting order for this field in group.

Element Detail

name

public abstract String name

Group index name where this field participate.

Returns:

Group index name

order

public abstract int order

Fields in this group index will be sorted on this attribute.

Returns:

Order number.

descending

public abstract boolean descending

Defines sorting order for this field in group.

Returns:

True if field will be in descending order.

Default:

false