Available in versions: Dev (3.21) | Latest (3.20) | 3.19 | 3.18 | 3.17 | 3.16 | 3.15 | 3.14 | 3.13 | 3.12 | 3.11
CONNECT_BY_ISCYCLE
Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition
The CONNECT_BY_ISCYCLE pseudo column allows for detecting if the current row has a child which is also the row's ancestor.
SELECT
child,
parent,
sys_connect_by_path(child, '/'),
connect_by_iscycle
FROM (
VALUES
(1, null),
(2, 1),
(3, 2),
(2, 3)
) AS t (child, parent)
START WITH
parent IS NULL
CONNECT BY NOCYCLE
PRIOR child = parent;
Field<Integer> child = field("child", INTEGER);
Field<Integer> parent = field("parent", INTEGER);
create.select(
child,
parent,
sysConnectByPath(child, "/"),
connectByIsCycle())
.from(values(
row(val(1), val(null, INTEGER)),
row(2, 1),
row(3, 2),
row(2, 3)).as(table("t"), child, parent))
.startWith(parent.isNull())
.connectByNoCycle(prior(child).eq(parent))
.fetch();
The result being, for example
+-------+--------+--------+--------------------+ | child | parent | path | connect_by_iscycle | +-------+--------+--------+--------------------+ | 1 | | /1 | 0 | | 2 | 1 | /1/2 | 0 | | 3 | 2 | /1/2/3 | 1 | +-------+--------+--------+--------------------+
Dialect support
This example using jOOQ:
connectByIsCycle()
Translates to the following dialect specific expressions:
Exasol, Informix, Oracle
connect_by_iscycle
ASE, Access, Aurora MySQL, Aurora Postgres, BigQuery, ClickHouse, CockroachDB, DB2, Databricks, Derby, DuckDB, Firebird, H2, HSQLDB, Hana, MariaDB, MemSQL, MySQL, Postgres, Redshift, SQLDataWarehouse, SQLServer, SQLite, Snowflake, Sybase, Teradata, Trino, Vertica, YugabyteDB
/* UNSUPPORTED */
Generated with jOOQ 3.21. Support in older jOOQ versions may differ. Translate your own SQL on our website
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