在Oracle结果集中添加自增序号的6种实现方式

SELECT 
    ROWNUM AS row_num,
    column1, 
    column2
FROM your_table
WHERE ROWNUM <= 100
ORDER BY some_column;

SELECT 
    ROW_NUMBER() OVER (ORDER BY some_column) AS row_num,
    column1, 
    column2
FROM your_table;

-- RANK()：相同值会有相同序号，下一个不同值会跳过相应位置
SELECT 
    RANK() OVER (ORDER BY some_column) AS rank_num,
    column1, 
    column2
FROM your_table;

-- DENSE_RANK()：相同值有相同序号，但不会跳过序号
SELECT 
    DENSE_RANK() OVER (ORDER BY some_column) AS dense_rank_num,
    column1, 
    column2
FROM your_table;

SELECT 
    ROW_NUMBER() OVER (PARTITION BY dept_id ORDER BY salary DESC) AS dept_rank,
    employee_id,
    name,
    salary,
    dept_id
FROM employees;

SELECT 
    ROWNUM AS row_num,
    t.*
FROM (
    SELECT column1, column2
    FROM your_table
    ORDER BY some_column
) t;

-- 11-20条记录（第二页，每页10条）
SELECT * FROM (
    SELECT 
        ROW_NUMBER() OVER (ORDER BY some_column) AS row_num,
        t.*
    FROM your_table t
)
WHERE row_num BETWEEN 11 AND 20;