SQL Server 2017

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CREATE TABLE A (
ci004 varchar(40) NULL ,
ci005 varchar(40) NULL ,
ci006 varchar(40) NULL);

INSERT INTO A (ci004,ci005,ci006)
VALUES 
('20200127','20200128','20200129'),
('2021-01-27','2021-01-28','2021-01-29'),
('2022-01-27','20220128','20230129');

SELECT *
FROM A;


ci004
ci005
ci006


20200127
20200128
20200129

2021-01-27
2021-01-28
2021-01-29

2022-01-27
20220128
20230129


UPDATE X
SET ci004=REPLACE(ci004,'-',''),
ci005=REPLACE(ci005,'-',''),
ci006=REPLACE(ci006,'-','')
FROM A AS X
WHERE ci004 LIKE '%-%' OR ci005 LIKE '%-%' OR ci006 LIKE '%-%' 
2 rows affected

SELECT *
FROM A;


ci004
ci005
ci006


20200127
20200128
20200129

20210127
20210128
20210129

20220127
20220128
20230129

ci004	ci005	ci006
20200127	20200128	20200129
2021-01-27	2021-01-28	2021-01-29
2022-01-27	20220128	20230129