递归查询

1767. 寻找没有被执行的任务队

# 递归查询
# 生成一个包含数字 1 到 20 的递增数列
WITH RECURSIVE NumberSeries AS (  # 表名 NumberSeries
  SELECT 1 AS number
  UNION ALL
  SELECT number + 1
  FROM NumberSeries
  WHERE number < 20
)
SELECT number FROM NumberSeries;  # 字段名：number

答案：

WITH RECURSIVE NumberSeries AS (
  SELECT 1 AS number
  UNION ALL
  SELECT number + 1
  FROM NumberSeries
  WHERE number < 20
)

select task_id, subtask_id from
(
    select task_id, number subtask_id from Tasks, NumberSeries where
    subtasks_count >= number) temp
    where (task_id, subtask_id) NOT IN
    (select task_id, subtask_id from Executed);