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Rollup

Definition​

The rollup method allows you to add the ROLLUP subclause to the query.

The ROLLUP subclause is a short way to define multiple grouping sets so the following are equivalent:

ROLLUP(k1, k2, k3) 

GROUPING SETS (
    (k1, k2, k3), 
    (k1, k2),
    (k1),
    ()
 )

Available methods​

1. rollup(KColumn... kColumns)​

  • kColumns: are all the expresions that will be added to the ROLLUP subclause.
    Among the possible values are: KTableColumn, KColumn.
tip

The use of this method is recommended in statements that involve the GROUP BY clause.

To use this method, you need to import the static functions as follows:

import static com.myzlab.k.KFunction.*;

Example​

Java code:

k
.select(
    count(),
    APP_USER.CREATED_AT.cast(date()),
    APP_USER.ROLE_ID,
    grouping(APP_USER.CREATED_AT.cast(date())),
    grouping(APP_USER.ROLE_ID)
)
.from(APP_USER)
.groupBy(
    rollup(APP_USER.CREATED_AT.cast(date()), APP_USER.ROLE_ID)
)
.multiple();

SQL generated:

SELECT
    COUNT(*),
    CAST(au.created_at AS DATE),
    au.role_id,
    GROUPING(CAST(au.created_at AS DATE)),
    GROUPING(au.role_id)
FROM app_user au
GROUP BY 
    ROLLUP(CAST(au.created_at AS DATE), au.role_id)

Parameters:

  • None