如何利用这个SQL进行删除出现次数>2的公司，使>2的公司出现次数为1：SELECT company_name, COUNT() AS count FROM ( SELECT company_name, DENSE_RANK() OVER (ORDER BY company_name) AS company_rank FROM your_table_name ) AS subquery GROUP BY company_name HAVING COUNT() > 1;

要将出现次数大于2的公司出现次数变为1，可以使用以下SQL语句：

UPDATE your_table_name
SET company_name = 'new_name'
WHERE company_name IN (
    SELECT company_name
    FROM (
        SELECT company_name, COUNT(*) AS count
        FROM (
            SELECT company_name, DENSE_RANK() OVER (ORDER BY company_name) AS company_rank
            FROM your_table_name
        ) AS subquery
        GROUP BY company_name
        HAVING COUNT(*) > 2
    ) AS subquery2
);

DELETE FROM your_table_name
WHERE company_name IN (
    SELECT company_name
    FROM (
        SELECT company_name, COUNT(*) AS count
        FROM (
            SELECT company_name, DENSE_RANK() OVER (ORDER BY company_name) AS company_rank
            FROM your_table_name
        ) AS subquery
        GROUP BY company_name
        HAVING COUNT(*) > 2
    ) AS subquery3
);

这个语句会先将表中所有公司按照名称进行排序，并计算它们的排名。然后，将它们分组并计算每个公司出现的次数。接着，将出现次数大于2的公司名称提取出来，并将这些公司的名称更新为一个新的名称，例如'new_name'。最后，将这些公司的所有记录从原表中删除。这样就可以将出现次数大于2的公司出现次数变为1。