mysql remove duplicate data

mysql remove duplicate data
Query duplicate data according to one column (judging duplicate data according to single column)
SELECT * FROM tab_test
WHERE ONE IN (SELECT ONE FROM testdelete GROUP BY ONE HAVING COUNT(ONE) >1)
Delete duplicate records in the table: (delete according to a single column and keep the one with the smallest ID)
DELETE
FROM tab_test
WHERE ONE IN(SELECT
ONE
FROM (SELECT
ONE
FROM tab_test
GROUP BY ONE
HAVING COUNT(ONE) > 1) a)
AND id NOT IN(SELECT
*
FROM (SELECT
MIN(id)
FROM tab_test
GROUP BY ONE
HAVING COUNT(ONE) > 1) b);

Judging repetition according to one,two,three: (Judging repetition according to single and multiple)
SELECT * FROM tab_test a
WHERE (a.one,a.two,a.three) IN
(SELECTONE,two,three FROM tab_test GROUP BY ONE,two,three HAVING COUNT(*) > 1) ;

Delete duplicate data in the table (delete according to multiple columns and keep the one with the smallest ID)
DELETE
FROM tab_test
WHERE (ONE,two,three)IN(SELECT
ONE,
two,
three
FROM (SELECT
ONE,
two,
three
FROM tab_test
GROUP BY ONE,two,three
HAVING COUNT(* ) > 1) a)
AND id NOT IN(SELECT
MIN(id)
FROM (SELECT
MIN(id) AS id
FROM tab_test
GROUP BY ONE,two,three
HAVING COUNT( * ) > 1) b)

Find redundant duplicate records (multiple fields) in the table, excluding the record with the smallest id (check duplicates based on multiple fields but not include the smallest id)
SELECT *
FROM tab_test a
WHERE(a.one,a.two,a.three)IN(SELECT
ONE,
two,
three
FROM tab_test
GROUP BY ONE,two,three
HAVING COUNT( * ) > 1)
AND id NOT IN(SELECT
MIN(id) AS id
FROM tab_test
GROUP BY ONE,two,three
HAVING COUNT( * ) > 1);

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