1select variable_name from information_schema.session_status where variable_name = 2(select variable_name from information_schema.session_status where variable_name = 'uptime'); 3variable_name 4UPTIME 5select variable_name from information_schema.session_variables where variable_name = 6(select variable_name from information_schema.session_variables where variable_name = 'basedir'); 7variable_name 8BASEDIR 9create table t1 (x int); 10create table t2 (x int); 11create table t3 (x int); 12create table t4 AS select table_name from information_schema.TABLES where table_schema = database() and table_type = 'BASE TABLE' ; 13delete from t4 where table_name not in (select table_name from information_schema.TABLES where table_schema = database() and table_type = 'BASE TABLE'); 14select * from t4 order by table_name; 15table_name 16t1 17t2 18t3 19t4 20drop table t1, t2, t3, t4; 21