我有一张帐单数据表，看起来像这样：
+-----------------------+------------+------------+-------------+---------+
| segment | Product | custname | prod_yr_mth | revenue |
+-----------------------+------------+------------+-------------+---------+
| PUBLIC SECTOR | product 1 | customer a | 201806 | 318.34 |
| LARGE ENTERPRISE | product 2 | customer b | 201902 | 8.96 |
| SMALL MEDIUM BUSINESS | product 3 | customer c | 201907 | -10 |
| SMALL MEDIUM BUSINESS | product 4 | customer d | 201804 | 0 |
| SMALL MEDIUM BUSINESS | product 5 | customer e | 201809 | 9.33 |
| LARGE ENTERPRISE | product 1 | customer f | 201901 | 155.75 |
| PUBLIC SECTOR | product 6 | customer g | 201905 | 24.32 |
| SMALL MEDIUM BUSINESS | product 2 | customer h | 201812 | 0.25 |
| SMALL MEDIUM BUSINESS | product 2 | customer i | 201801 | 5.46 |
| LARGE ENTERPRISE | product 7 | customer j | 201805 | 4.5 |
| LARGE ENTERPRISE | product 1 | customer k | 201812 | 0 |
| SMALL MEDIUM BUSINESS | product 8 | customer l | 201809 | 2.99 |
| LARGE ENTERPRISE | product 2 | customer m | 201812 | 0.71 |
| LARGE ENTERPRISE | product 1 | customer n | 201902 | 0 |
| PUBLIC SECTOR | product 2 | customer o | 201803 | 1.08 |
| SMALL MEDIUM BUSINESS | product 9 | customer p | 201802 | 10.27 |
| LARGE ENTERPRISE | product 10 | customer a | 201905 | 52.99 |
| PUBLIC SECTOR | product 1 | customer b | 201810 | 7 |
| SMALL MEDIUM BUSINESS | product 3 | customer c | 201906 | 40 |
+-----------------------+------------+------------+-------------+---------+
我想获得按业务部门分组的每种产品的净新客户数。
因此，本月prod_yr_mth列中的最大日期为201908。如果该客户购买该产品的最早价值是201908，我将认为该客户是“新用户”。
最终结果应如下所示：
+-----------------------+------------+-------------------+
| seg_lvl5_2 | Product | Net_New_Customers |
+-----------------------+------------+-------------------+
| LARGE ENTERPRISE | product 1 | 0 |
| LARGE ENTERPRISE | product 10 | 5 |
| LARGE ENTERPRISE | product 2 | 6 |
| LARGE ENTERPRISE | product 6 | 1 |
| LARGE ENTERPRISE | product 7 | 2 |
| PUBLIC SECTOR | product 1 | 3 |
| PUBLIC SECTOR | product 2 | 1 |
| PUBLIC SECTOR | product 5 | 1 |
| PUBLIC SECTOR | product 6 | 1 |
| SMALL MEDIUM BUSINESS | product 1 | 1 |
| SMALL MEDIUM BUSINESS | product 2 | 0 |
| SMALL MEDIUM BUSINESS | product 3 | 9 |
| SMALL MEDIUM BUSINESS | product 4 | 8 |
| SMALL MEDIUM BUSINESS | product 5 | 7 |
| SMALL MEDIUM BUSINESS | product 6 | 3 |
| SMALL MEDIUM BUSINESS | product 8 | 4 |
| SMALL MEDIUM BUSINESS | product 9 | 5 |
| SMALL MEDIUM BUSINESS | product 10 | 2 |
+-----------------------+------------+-------------------+
谢谢！
我有一张帐单数据表，看起来像这样：+ ----------------------- + ----------- -+ ------------ + ------------- + --------- + |段|产品展示客户名称| prod_yr_mth | ...
如果我的理解正确，您希望将客户/产品的最早日期与表中的最新日期进行比较。如果是这样：