小编Sin*_*chi的帖子

在SQLite中,我需要更新相关表的行计数.

下面的查询执行我想要的但是它多次遍历表以获取计数:

UPDATE overallCounts SET
  total = (count(*) FROM widgets WHERE joinId=1234),
  totalC = (count(*) FROM widgets WHERE joinId=1234 AND source=0),
  totalL = (count(*) FROM widgets WHERE joinId=1234 AND source=2),
  iic = (SELECT CASE WHEN COUNT(*)>0 THEN 1 ELSE 0 END FROM widgets WHERE joinId=1234 AND widgets.source=0),
  il = (SELECT CASE WHEN COUNT(*)>0 THEN 1 ELSE 0 END FROM widgets WHERE joinId=1234 AND widgets.source=2)
WHERE id=1234

这个查询准确地检索了我想要的内容,但我需要将其输出转换为更新语句:

SELECT
  count(*) as total,
  sum(case when source=0 then 1 else 0 end) as …