SHOW INDEX FROM bonus ; // 查看表bonus中的索引
CREATE UNIQUE INDEX bonus_ ON bonus(`value`); // 给表bonus的value字段创建索引 bonus_
DROP INDEX bonus_ ON bonus ; // 删除表中bonus的索引
SHOW INDEX FROM bonus ; // 查看表bonus中的索引
CREATE UNIQUE INDEX bonus_ ON bonus(`value`); // 给表bonus的value字段创建索引 bonus_
DROP INDEX bonus_ ON bonus ; // 删除表中bonus的索引