MySql如何手动获取自增主键

select nextval('TESTDATA') AS batchId
CREATE DEFINER=`admin`@`%` FUNCTION `nextval`(seq_name VARCHAR (50)) RETURNS bigint(20)
BEGIN
 UPDATE
 SEQUENCES
 SET
 last_number = last_number + increment_by
 WHERE sequence_name = seq_name;
 RETURN currval (seq_name);
END;

CREATE DEFINER=`admin`@`%` FUNCTION `currval`(seq_name VARCHAR (50)) RETURNS bigint(20)
 NO SQL
BEGIN
 
 SELECT
 last_number INTO @VALUE
 FROM
 SEQUENCES
 WHERE sequence_name = seq_name;
 RETURN @VALUE;
END;

DROP TABLE IF EXISTS `sequences`;
CREATE TABLE `sequences` (
 `sequence_owner` varchar(30) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
 `sequence_name` varchar(30) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
 `min_value` bigint(20) NULL DEFAULT 1,
 `max_value` bigint(20) NULL DEFAULT NULL,
 `increment_by` bigint(20) NOT NULL DEFAULT 1,
 `cycle_flag` varchar(1) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NULL DEFAULT NULL,
 `order_flag` varchar(1) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NULL DEFAULT NULL,
 `cache_size` bigint(20) NOT NULL,
 `last_number` bigint(20) NOT NULL,
 PRIMARY KEY (`sequence_name`) USING BTREE,
 UNIQUE INDEX `sel`(`sequence_owner`, `sequence_name`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_bin ROW_FORMAT = Compact;
 
-- ----------------------------
-- Records of sequences
-- ----------------------------
INSERT INTO `sequences` VALUES ('SCM', 'TESTDATA', 1, 9999999999, 1, 'N', 'Y', 20, 0);
INSERT INTO `sequences` VALUES ('SCM', 'SEQ', 1, 9999999999, 1, 'N', 'N', 20, 0);
 
SET FOREIGN_KEY_CHECKS = 1;