将第二行与上一行进行比较:
SELECT cur.date, prev.color "before", cur.color now
FROM tbl cur
LEFT JOIN tbl prev ON cur.id = prev.id + 1
WHERE cur.id > 1 -- start detecting changes from second row
AND prev.color <> cur.color
现场测试:http ://sqlfiddle.com/#!2/0c146/1
编辑
即使在不连续的数据中也能工作。如果 MySQL 中有 CTE 功能,查询可能会更简洁
create table tbl
(
id int,
date date,
color text
);
insert into tbl(id,date,color)
select 1,'2012-1-1','black' union
select 2,'2012-1-3','red' union
select 3,'2012-1-7','red' union
select 4,'2012-1-15','red' union
select 5,'2012-1-21','green' ;
set @rx = 0;
set @ry = 0;
select cur.date, prev.color as "before", cur.color as "now"
from (select *, @ry := @ry + 1 as series from tbl order by date) as cur
left join (select *, @rx := @rx + 1 as series from tbl order by date) as prev
on cur.series = prev.series + 1
where cur.series > 1
and prev.color <> cur.color
现场测试:http ://sqlfiddle.com/#!2/b9443/2