题解 | #返回每个订单号各有多少行数#

SELECT 
    order_num,
    COUNT(order_num) order_lines
FROM
    OrderItems
GROUP BY
    order_num
ORDER BY
    order_lines;
#【问题】编写 SQL 语句，返回每个订单号（order_num）各有多少行数（order_lines），并按 order_lines对结果进行升序排序