for example, the statement
select * from table_a join table_b on table_a.id=table_b.a_id and table_a.name="smith" join table_c where table_a.priority=3 and table_b.seq=8 and table_c.sales=1998;
in the operation of embedded loops in concatenated tables, if table_a is the driver table
1) table_a does the first layer circular set according to the result set after table_a.name="smith" Filter in the on condition, and so on. Wait until the temporary table generated by an on bmemorie c join table and then do Filter according to the condition in the where statement
2) table_a according to the table_a.name="smith" in the on condition and the result set after the where condition in the first layer circular set, and so on
actually means to understand the execution order of on and where
which is right?