How to use CTE's with update/delete on SQLite?

问题:

SQLite now has CTEs, and the documentation says you can use it with insert, update and delete queries -- but only gives examples of select statements.

I can figure out how CTEs apply to inserts, via insert-select; but how can we use them in update or delete, where there is no from-clause?

回答1:

CTEs can be used in subqueries:

WITH NewNames(ID, Name) AS (...)
UPDATE MyTable
SET Name = (SELECT Name
            FROM NewNames
            WHERE ID = MyTable.ID);

WITH IDsToDelete AS (...)
DELETE FROM MyTable
WHERE ID IN IDsToDelete;