sql-如何在一个查询中组合选择列，计数和比较？

Question

通过使用SQL命令，列出idworker，来自worker table的nameworker和total_late，用于“迟到”记录超过1次的工人。

Answer 1

试试这个（假设有一个Late表，当工人迟到时每次出现一条记录）：

SELECT w.idworker, w.nameworker, l.total_late
FROM Worker w LEFT JOIN 
(SELECT idworker, SUM(late) as total_late, COUNT(*) AS number_late 
 FROM Late GROUP BY idworker) l ON w.idworker = l.idworker
WHERE number_late > 1