在已有的表中添加主鍵自增
ALTER TABLE `表名` MODIFY COLUMN `id` int(11) NOT NULL AUTO_INCREMENT FIRST ,ADD PRIMARY KEY (`id`);
刪除數據讓主鍵重新從1開始
SET foreign_key_checks=0;
TRUNCATE tb_shop;
SET foreign_key_checks=1;
ALTER TABLE `表名` MODIFY COLUMN `id` int(11) NOT NULL AUTO_INCREMENT FIRST ,ADD PRIMARY KEY (`id`);
SET foreign_key_checks=0;
TRUNCATE tb_shop;
SET foreign_key_checks=1;