package cn.palmte.work.service;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

/**
 * @author Yuanping Zhang
 * @date 2022/08/08
 */
@Service
public class NumSeqService {
    private static final Logger logger = LoggerFactory.getLogger(NumSeqService.class);

    @Autowired
    @PersistenceContext
    private EntityManager entityManager;

    public String generate() {
        String prefix = "P";
        String querySql = "select num from num_seq limit 1";
        Query nativeQuery = entityManager.createNativeQuery(querySql);
        int num = (Integer)nativeQuery.getSingleResult();
        String counterString = String.format("%05d", num++);
        entityManager.createNativeQuery("update num_seq set num = " + num);
        return prefix + counterString;
    }
}