Question

我如何获得所有客户，但不能获得已在CURRENT月份注册的记录？我认为这会起作用，但不是 - 该怎么办？

SELECT * FROM customers WHERE deleted = 0 AND (MONTH(created) != MONTH(NOW() AND YEAR(created) != YEAR(NOW())))

Answer 1

SELECT * FROM customers 
   WHERE (deleted = 0) AND  not (
         (MONTH(created) = MONTH(NOW()) AND 
         (YEAR(created) = YEAR(NOW()))

Answer 2

作为一项基本规则，您应该避免使用列上的计算器，这会导致CPU使用率增加，并且无法使用索引。

标准的SQL兼容解决方案（也适用于MySQL）只是找到上个月的最后一天：

SELECT * FROM customers 
WHERE deleted = 0
  AND created <= CURRENT_DATE - EXTRACT(DAY FROM CURRENT_DATE)

Answer 3

MONTH(NOW()应该有一个结束括号，即： - MONTH(NOW())

MONTH(created) != MONTH(NOW())将过滤掉创建日期月份不等于当月的客户并YEAR(created) = YEAR(NOW())将过滤当前年度

SELECT * FROM customers 
WHERE deleted = 0 
and MONTH(created) != MONTH(NOW()) 
and YEAR(created) = YEAR(NOW())

Answer 4

试试这个

 SELECT * FROM customers  WHERE deleted = 0 AND  not (
             (MONTH(created) = MONTH(NOW()) AND 
             (YEAR(created) = YEAR(NOW()))

或

SELECT * FROM customers WHERE deleted = 0 AND !( (MONTH(created) = MONTH(NOW()) AND (YEAR(created) = YEAR(NOW()))

Answer 5

您应该将AND更改为OR：

select 
    * 
from 
    customers 
where 
    deleted = 0 
    and 
    (
        year(created) != year(now()) or month(created) != month(now())

    );

选择所有客户，但不是当前月份

5 个答案: