使用另一个表更新mysql表多列

Question

我有以下表格（ 表格：avg_month_val1 ）

year                       
month        
evep                
sunshine_hrs             
rainfall     
max_temp               
min_temp  

和

（ 表：reg_data3 ）

id         
date                
time                  
rainfall                
evep                         
max_temp                   
min_temp    
sunshine_hrs

我想使用reg_data3更新avg_month_val1表，我遵循如何从mysql中的另一个表更新多个字段？

这是我的查询

UPDATE `avg_month_val1` a,`reg_data3` b SET
a.`year`=YEAR(b.`date`),
a.`month`=MONTH(b.`date`),
a.`evep`=ROUND(AVG(b.evep),2),
a.`max_temp`=ROUND(AVG(b.max_temp),2), 
a.`min_temp`=ROUND(AVG(b.min_temp),2) ,
a.`rainfall`=ROUND(SUM(b.rainfall),2), 
a.`sunshine_hrs`=ROUND(AVG(b.sunshine_hrs),2)
WHERE a.`year`=YEAR(b.`date`)

但它给出以下错误

Error Code: 1111
Invalid use of group function

我如何做到这一点

Answer 1

这样尝试

UPDATE avg_month_val1 t JOIN 
(
  SELECT YEAR(date) year,
         MONTH(date) month,
         ROUND(AVG(evep), 2) evep,
         ROUND(AVG(max_temp), 2) max_temp,
         ROUND(AVG(min_temp), 2) min_temp,
         ROUND(SUM(rainfall), 2) rainfall,
         ROUND(AVG(sunshine_hrs), 2) sunshine_hrs
    FROM reg_data3
   GROUP BY YEAR(date), MONTH(date)
) s 
    ON t.year = s.year
   AND t.month = s.month
   SET t.evep = s.evep,
       t.max_temp = s.max_temp, 
       t.min_temp = s.min_temp, 
       t.rainfall = s.rainfall, 
       t.sunshine_hrs = s.sunshine_hrs 

使用UPDATE意味着你已经在表avg_month_val1与列的行year和month填充，只需要更新数据列（ evep从累计值，...） reg_data3 。

但是，如果不是这种情况，并且您想INSERT所有列（包括year和month但是能够使用相同的年和月值更新现有行，则可以使用ON DUPLICATE KEY子句

INSERT INTO avg_month_val1 (year, month, evep, max_temp, min_temp, rainfall, sunshine_hrs)
SELECT YEAR(date) year,
       MONTH(date) month,
       ROUND(AVG(evep), 2) evep,
       ROUND(AVG(max_temp), 2) max_temp,
       ROUND(AVG(min_temp), 2) min_temp,
       ROUND(SUM(rainfall), 2) rainfall,
       ROUND(AVG(sunshine_hrs), 2) sunshine_hrs
  FROM reg_data3
 GROUP BY YEAR(date), MONTH(date)
 ON DUPLICATE KEY UPDATE
       evep = VALUES(evep),
       max_temp = VALUES(max_temp), 
       min_temp = VALUES(min_temp), 
       rainfall = VALUES(rainfall), 
       sunshine_hrs = VALUES(sunshine_hrs)

为了使其正常工作，您必须确保avg_month_val1 （年，月）具有UNIQUE或PRIMARY KEY约束