为mysql 表重新设置自增的主键id
1，删除原有主键：
ALTER TABLE `table_name` DROP `id`;
2，添加新主键字段：
ALTER TABLE `table_name` ADD `id` INT NOT NULL FIRST;
3，设置新主键：
ALTER TABLE `table_name` MODIFY COLUMN `id` INT NOT NULL AUTO_INCREMENT,ADD PRIMARY KEY(id);
ALTER TABLE `table_name` DROP `id`;
ALTER TABLE `table_name` ADD `id` INT NOT NULL FIRST;
ALTER TABLE `table_name` MODIFY COLUMN `id` INT NOT NULL AUTO_INCREMENT,ADD PRIMARY KEY(id);