(original) MySQL error 1093 you can ' t specify target table ' Wms_cabinet_form ' for update in FROM clause

This error means that you cannot select some of the values in the same table, then update the table (in the same statement), the solution does not directly query the same, assuming that the table to be updated to a, the data of a is first put to table B, and then query from table B to get updated and query table a effect

Cases:

Score Table:

Change the grade of the "Yao" teacher taught in the "SC" table to the average grade of this course

Update SC Set score= (select AVG (a.score) from (select Score,c to SC) a where A.C in (select C from Course l EFT Join teacher on course. T=teacher. T where Tname= ' Yao ') group by A.C) where C in (select C from course left join teacher on course. T=teacher. T where Tname= ' Yao Ming ')

Where the red font will put the SC data into a temporary table A, and then query the table A

(original) MySQL error 1093 you can ' t specify target table ' Wms_cabinet_form ' for update in FROM clause