MySQL使用Sequence创建唯一主键的实现示例

CREATE TABLE `mysql_sequence` (
  `seq_name` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL COMMENT '序列名称',
  `seq_desc` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL COMMENT '序列描述',
  `seq_no` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL COMMENT '序列号',
  `max_val` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL,
  PRIMARY KEY (`seq_name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin

DELIMITER $$
CREATE  FUNCTION `nextval`(v_seq_name VARCHAR(50)) RETURNS INT
DETERMINISTIC
BEGIN
    UPDATE mysql_sequence SET seq_no = seq_no + 1 WHERE seq_name = v_seq_name AND seq_no <= max_val;
    UPDATE mysql_sequence SET seq_no = 1 WHERE seq_name = v_seq_name AND seq_no > max_val;
    RETURN currval(v_seq_name);
END$$
DELIMITER ;

DELIMITER $$
CREATE  FUNCTION currval(v_seq_name VARCHAR(50)) RETURNS INT
BEGIN
    DECLARE seq_val INT;
    SET seq_val = 0;
    SELECT seq_no INTO seq_val FROM mysql_sequence WHERE seq_name = v_seq_name;
    RETURN seq_val;
END$$
DELIMITER ;

DELIMITER $$
CREATE  FUNCTION `timeseq`(v_seq_name VARCHAR(50), v_lpad INT) RETURNS VARCHAR(50) CHARSET utf8mb4 COLLATE utf8mb4_bin
BEGIN
    DECLARE seq_val VARCHAR(50);
    SELECT CONCAT(DATE_FORMAT(CURRENT_TIMESTAMP(), '%Y%m%d'), LPAD(nextval(v_seq_name), v_lpad, '0')) INTO seq_val FROM dual;
    RETURN seq_val;
END$$
DELIMITER ;

SELECT CONCAT(DATE_FORMAT(CURRENT_TIMESTAMP(), '%Y%m%d'), LPAD(nextval('stud_seq'), 4, '0'))  FROM dual;

@Data
@Entity
@Table(name = "mysql_sequence")
public class MysqlSequence {
    @Id
    private String SeqName;
    private String SeqDesc;
    private String SeqNo;
}

import com.icbc.sh.dto.MysqlSimpleSequence;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.data.jpa.repository.Modifying;

public interface SequenceRepo extends JpaRepository<MysqlSimpleSequence, String> {

    // 获取下一个序列值
    @Query(value = "select nextval(:seqName) from dual", nativeQuery = true)
    int nextval(@Param("seqName") String seqName);

    // 获取带填充的时间序列下一个值
    @Query(value = "select timeSeq(:seqName, :lpad) from dual", nativeQuery = true)
    String timeSeqNextVal(@Param("seqName") String seqName, @Param("lpad") int lpad);

    // 重置序列
    @Transactional
    @Modifying
    @Query(value = "update sequence set val = 1 where reset_flag = ?1", nativeQuery = true)
    int resetSeq(String resetFlag);
}

@RestController
@RequestMapping("/test")
public class TestController {

    @Autowired
    private SequenceRepo sequenceRepo;

    @GetMapping("/testSequence")
    public void testSequence(){
        int sequence = sequenceRepo.nextval("stud_seq");
        log.info("sequence :" + sequence);
    }
}