MYSQL 当有两条重复数据时 保留一条

delete from test where id in (select id from (select max(id) as id,count(text) as count from test group by text having count >1 order by count desc) as tab )

测试代码

INSERT IGNORE INTO test_1(text,text2) values ('1111','22222'); INSERT IGNORE INTO test_1(text,text2) values ('1111','22222'); INSERT IGNORE INTO test_1(text,text2) values ('1111','22222'); INSERT IGNORE INTO test_1(text,text2) values ('1111','22222'); INSERT IGNORE INTO test_1(text,text2) values ('1111','22222'); INSERT IGNORE INTO test_1(text,text2) values ('1111','33333'); INSERT IGNORE INTO test_1(text,text2) values ('1111','33333'); INSERT IGNORE INTO test_1(text,text2) values ('1111','33333'); INSERT IGNORE INTO test_1(text,text2) values ('1111','33333'); INSERT IGNORE INTO test_1(text,text2) values ('1111','33333'); INSERT IGNORE INTO test_1(text,text2) values ('1111','33333'); INSERT IGNORE INTO test_1(text,text2) values ('1111','33333');
INSERT IGNORE INTO test_1(text,text2) values ('22222','33333'); INSERT IGNORE INTO test_1(text,text2) values ('22222','33333'); INSERT IGNORE INTO test_1(text,text2) values ('22222','33333'); INSERT IGNORE INTO test_1(text,text2) values ('22222','33333'); INSERT IGNORE INTO test_1(text,text2) values ('22222','33333'); INSERT IGNORE INTO test_1(text,text2) values ('22222','33333');

REPLACE INTO test(text) values ('1111')
delete from test
select * from test_1 where text='1111'select * from test_1 where text='22222'
while delete from test_1 where id in (select id from (select max(id) as id,count(text) as count from test_1 where text = '22222' group by text,text2 having count >1 order by count desc) as tab );
delete from test_1 where id in (select id from (select max(id) as id,count(text) as count from test_1 where text = '22222' group by text,text2 having count >1 order by count desc) as tab );delete from test_1 where id in (select id from (select max(id) as id,count(text) as count from test_1 where text = '22222' group by text,text2 having count >1 order by count desc) as tab );delete from test_1 where id in (select id from (select max(id) as id,count(text) as count from test_1 where text = '22222' group by text,text2 having count >1 order by count desc) as tab );delete from test_1 where id in (select id from (select max(id) as id,count(text) as count from test_1 where text = '22222' group by text,text2 having count >1 order by count desc) as tab );delete from test_1 where id in (select id from (select max(id) as id,count(text) as count from test_1 where text = '22222' group by text,text2 having count >1 order by count desc) as tab );delete from test_1 where id in (select id from (select max(id) as id,count(text) as count from test_1 where text = '22222' group by text,text2 having count >1 order by count desc) as tab );delete from test_1 where id in (select id from (select max(id) as id,count(text) as count from test_1 where text = '22222' group by text,text2 having count >1 order by count desc) as tab );

来自为知笔记(Wiz)