在上表中，查询num中不包含3的id, sql怎么写？谢谢.用not in 筛选不出来

假设表名为Persons。

可用如下sql语句

 select distinct id from Persons where id not in (select id from Persons where num = 3);

备注：不加distinct，结果为3 3

         加distinct,结果为3

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select .... from ... where id <> 3;