MySQL execution order

1. from Clause : The left and right tables are Cartesian products
2. join The way : If it is inner join That's normal , If it is outer join Then some lines filtered in the previous step will be added back
3. on Conditions : Filter the data that meets the conditions
4. where Conditions : Removing rows that do not meet the conditions does not restore
5. group by grouping : After grouping, only one row or aggregate function of each group can be obtained
6. with cube/rollup: Form supergroup
7. having Screening : Filter the groups
8. select Inquire about : Filter out the required columns
9. distinct duplicate removal : Remove duplicate lines
10. order by Sort
11. limit limit : Determine how many lines need to be returned