MySQL `AUTO_INCREMENT` 属性详解：为什么第一条数据的 ID 从 0 开始？

这段SQL语句中的AUTO_INCREMENT属性指定了id字段的自增起始值为0，即第一条数据的id值会从0开始自增。\n\nDROP TABLE IF EXISTS role_tbl;\nCREATE TABLE role_tbl (\n id int(11) NOT NULL AUTO_INCREMENT,\n name varchar(32) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,\n code varchar(100) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL,\n type tinyint(4) NOT NULL,\n description varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL,\n enabled tinyint(4) NULL DEFAULT 1,\n updated_at timestamp NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,\n created_at timestamp NULL DEFAULT CURRENT_TIMESTAMP,\n created_by varchar(64) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL,\n updated_by varchar(64) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL,\n PRIMARY KEY (id) USING BTREE,\n UNIQUE INDEX uniq_role_tbl(name) USING BTREE\n) ENGINE = InnoDB AUTO_INCREMENT = 0 CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = COMPACT;