MySQL 8.0

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Create Table areas(NAME VARCHAR(50), SIZE INT, VALID_FROM INT, VALID_UNTIL INT);

Insert Into areas Values('area1',55,1990,2005),
('area1',40,2000,2009),
('area1',45,2010,2099),
('area2',79,1990,2099),
('area3',33,1990,1999),
('area3',37,2000,2009);

Records: 6  Duplicates: 0  Warnings: 0


select NAME, 'timeframes overlap!' AS Remark
from
(
  select *,
    VALID_FROM - lag(VALID_UNTIL) over (partition by NAME order by VALID_FROM) df
  from areas
) t
group by NAME
having sum(df <= 0) > 0 


NAME
Remark


area1
timeframes overlap!


select *,
  VALID_FROM - lag(VALID_UNTIL) over (partition by NAME order by VALID_FROM) df
from areas


NAME
SIZE
VALID_FROM
VALID_UNTIL
df


area1
55
1990
2005
null

area1
40
2000
2009
-5

area1
45
2010
2099
1

area2
79
1990
2099
null

area3
33
1990
1999
null

area3
37
2000
2009
1

NAME	SIZE	VALID_FROM	VALID_UNTIL	df
area1	55	1990	2005	null
area1	40	2000	2009	-5
area1	45	2010	2099	1
area2	79	1990	2099	null
area3	33	1990	1999	null
area3	37	2000	2009	1