Can I use… cycle … set … to … default … using


The cycle clause can be used to detect cycles in recursive queries based on selected expressions from the row.

WITH RECURSIVE path (from, to) AS (
   SELECT from, to
     FROM edges
    WHERE id = ?
UNION
   SELECT from, to
     FROM path
     JOIN edges ON edges.from = path.to
    CYCLE from SET c TO 'Y' DEFAULT 'N' USING path_array
) …

The example detects duplicates based on the value in the from column.

20052007200920112013201520172019BigQuery011.50Db2 (LUW)10.5.40MariaDB8.0.200MySQL19c1Oracle DB121PostgreSQL20191SQL Server3.33.01SQLite0Use cycle … restrict.1Supported without using …. Use cycle … restrict.

Normative References

The cycle … set … to … default … using clause is defined in ISO/IEC 9075:2016-2 as part of optional feature T131.

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