ERROR 1630 (42000): FUNCTION a.avg does not exist. Check the ‘Function Name Parsing and Resolution‘

mysql This error occurs when the query statement is running :

It doesn't feel like a sentence problem , But it's always been wrong , Looked up some other methods , It's no use finding out . Finally, analyze the error report carefully , There is no such thing a.avg. Then continue to explore and find that it is because avg Function problem .

Need to give avg Function statistics column rename : Because the column names that appear in the subquery are avg Function itself , And then in use , Parent query statement , You can't find this column . Just rename it .