mysql - 如何在sql中添加两个选择列的总和？

Question

我有一份报告，需要对两个选择列的结果求和。尝试了各种组合，但它不起作用。 这是我的 sql 查询

SELECT c.`ctv_name` AS locationbyctv ,
( SELECT IFNULL(SUM(1),0)  FROM 
  dedint_account_table d1,broadband_invoice b1
  WHERE d1.`account_id`=b1.`line_id` AND c.`ctv_id`=b1.`ctv_id` AND b1.`service_id` IN (12,29,82) AND d1.status='Activated'
    AND DATE(d1.activity_datetime)>='2019-10-15' AND  DATE(d1.activity_datetime)<='2019-11-30' )  AS a,

( SELECT  IFNULL(SUM(1),0) FROM 
  dedint_account_table d1,broadband_invoice b1,dedint_account_change_table dac 
  WHERE d1.`account_id`=b1.`line_id` AND c.`ctv_id`=b1.`ctv_id` AND b1.`service_id` IN (12,29,82) 
   AND dac.change_description='Activated-Account' AND dac.account_id=d1.id
    AND DATE(d1.activity_datetime)>='2019-10-15' AND  DATE(d1.activity_datetime)<='2019-11-30' ) AS b ,

FROM broadband_invoice b,broadband_ctv c,dedint_account_table d
 WHERE  
 c.`ctv_id`=b.`ctv_id` AND d.account_id=b.line_id
  GROUP BY c.`ctv_id`

结果是:

locationbyctv                 a       b      
----------------------------  ------  ------ 

SANTA ELENA TOWN            0       0      
VILLE VILLAGE               1       1               
PUNA GDA TOWN               2       1      
CORAL TOWN                  0       0      
PROSSO VILLAGE              0       3     
BEL CITY                    1       0    

预期结果是:

locationbyctv                 a+b           
    ----------------------------  

    SANTA ELENA TOWN            0             
    VILLE VILLAGE               2                      
    PUNA GDA TOWN               3             
    CORAL TOWN                  0             
    PROSSO VILLAGE              3            
    BEL CITY                    1           

Answer 1

您可以使用 + 运算符对两列值求和。

请参阅official documentation了解更多信息。