在SQL中更新多个记录

Question

如何使用SQL在单个语句中更新多个记录？:

UPDATE records
   SET name='abc' where id=3,
   SET name='def' where id=1

Answer 1

您可以简单地将更新与案例陈述相结合

UPDATE records
   SET name =
     CASE
       WHEN id = 3 THEN 'abc'
       WHEN id = 1 THEN 'def'
       ELSE name
     END

Answer 2

只需几条记录,您就可以使用:

update records
set name = case id
  when 1 then 'def'
  when 3 then 'abc'
end
where id in (1, 3)

更灵活的是创建一个可以加入更新的结果:

update r
set name = x.name
from records r
inner join (
  select id = 1, name = 'abc' union all
  select 3, 'def' union all
  select 4, 'qwe' union all
  select 6, 'rty'
) x on x.id = r.id

Answer 3

;WITH vals(id, name)
     AS (SELECT 3,'abc'
         UNION ALL
         SELECT 1,'def')
UPDATE r
SET    name = vals.name
FROM   records r
       JOIN vals
         ON vals.id = r.id