-- 查看表的所有索引show index from 't_name'

-- 判断某个索引是否存在，如果不存在则创建。DROP PROCEDURE IF EXISTS schema_change;  DELIMITER //CREATE PROCEDURE schema_change() BEGIN DECLARE  CurrentDatabase VARCHAR(100);SELECT DATABASE() INTO CurrentDatabase;IF NOT EXISTS (SELECT * FROM information_schema.statistics WHERE table_schema=CurrentDatabase AND table_name = 't_name' AND index_name = 'myindexName') THEN     ALTER TABLE `t_name` ADD Index 'myindexName' ( `columnName` )  USING BTREE;END IF;  END//   CALL schema_change();