在SQL中，RANK函数用于计算或分配排名值给结果集中的行。以下是RANK函数的一些常见用法：
SELECT column1, column2, RANK() OVER (ORDER BY column1) AS rank_value
FROM table_name;
SELECT column1, column2, DENSE_RANK() OVER (ORDER BY column1) AS rank_value
FROM table_name;
SELECT column1, column2, ROW_NUMBER() OVER (ORDER BY column1) AS rank_value
FROM table_name;
SELECT column1, column2, RANK() OVER (PARTITION BY column3 ORDER BY column1) AS rank_value
FROM table_name;
这些是RANK函数的一些常见用法，可以根据具体的需求选择适合的用法。
