Oracle删除重复记录只保留一条数据的几种方法

1、查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断

SELECT
	*
FROM
	people
WHERE
	peopleid IN (
		SELECT
			peopleid
		FROM
			people
		GROUP BY
			peopleid
		HAVING
			COUNT (peopleid) > 1
	)

2、删除表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断，只留有rowid最小的记录

DELETE
FROM
	people
WHERE
	peopleid IN (
		SELECT
			peopleid
		FROM
			people
		GROUP BY
			peopleid
		HAVING
			COUNT (peopleid) > 1
	)
AND ROWID NOT IN (
	SELECT
		MIN (ROWID)
	FROM
		people
	GROUP BY
		peopleid
	HAVING
		COUNT (peopleid) > 1
)

3、查找表中多余的重复记录（多个字段）

SELECT
	*
FROM
	vitae A
WHERE
	(A .peopleid, A .seq) IN (
		SELECT
			peopleid,
			seq
		FROM
			vitae
		GROUP BY
			peopleid,
			seq
		HAVING
			COUNT (*) > 1
	)

4、删除表中多余的重复记录（多个字段），只留有rowid最小的记录

DELETE
FROM
	vitae A
WHERE
	(A .peopleid, A .seq) IN (
		SELECT
			peopleid,
			seq
		FROM
			vitae
		GROUP BY
			peopleid,
			seq
		HAVING
			COUNT (*) > 1
	)
AND ROWID NOT IN (
	SELECT
		MIN (ROWID)
	FROM
		vitae
	GROUP BY
		peopleid,
		seq
	HAVING
		COUNT (*) > 1
)

5、查找表中多余的重复记录（多个字段），不包含rowid最小的记录

SELECT
	*
FROM
	vitae A
WHERE
	(A .peopleid, A .seq) IN (
		SELECT
			peopleid,
			seq
		FROM
			vitae
		GROUP BY
			peopleid,
			seq
		HAVING
			COUNT (*) > 1
	)
AND ROWID NOT IN (
	SELECT
		MIN (ROWID)
	FROM
		vitae
	GROUP BY
		peopleid,
		seq
	HAVING
		COUNT (*) > 1
)