Background information
Oracle supports Select for update and For update of column syntaxes, which are not different for a single table. They are both locking related rows that meet the conditions for a single table. For multiple tables, For update locks the rows that match the conditions in multiple tables, whereas For update of locks the rows in the corresponding tables based on the conditions. Examples:
Single Table
select * from test where id =10 for update
select * from test where id=10 for update id
NoteLock the row with id=10.
Multiple tables
select * from test inner join t1 on test.id=t1.id where test.id=10 for update
select * from test inner join t1 on test.id=t1.id where test.id=10 for update of test
NoteLock the rows test and t1 with id=10.
New solution
Currently, PolarDB only supports the syntax For update and does not support the syntax For update of. You can adjust the syntax to For update as appropriate based on business situations.