use database;
SHOW TABLES;

SELECT SCHEMA_NAME FROM information_schema.SCHEMATA;

SELECT TABLE_NAME FROM information_schema.TABLES where TABLE_SCHEMA = 'database';

SELECT COLUMN_NAME FROM information_schema.COLMNS where TABLE_SCHEMA = 'database' AND TABLE_NAME = 'table'; 

SELECT @@datadir;

SELECT @@basedir;

SELECT @@VERSION_COMPILE_OS;

SELECT VERSION();

/*!50817SELECT VERSION();*/

/*!00000SELECT VERSION();*/

SELECT CONNECTION_ID();

SHOW PROCESSLIST;