In @Table(name = “tableName”) - make “tableName” a variable in JPA

Question

I am using JPA and I need to make the \"tableName\" a variable.

In a database, I have many tables, and my code needs to access the table where I specify it to read.

Answer 1

I have a workaround.
It uses javax.persistence.EntityManager and String.format to do that.

package com.example.test.dao;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.List;
import javax.persistence.EntityManager;

@Component
public class SomeDao {
    @Autowired
    EntityManager em;

    public List listFoodMoneyDateOfPayment(int departmentId, String sumKey, String tableName) {
        String s = "SELECT SUM(%s) AS money, CONCAT(YEAR(apply_time), '-', MONTH(apply_time)) AS yearmonth " +
                "FROM (%s) WHERE department_id = %d GROUP BY yearmonth";
        String sql = String.format(s, sumKey, tableName, departmentId);
        System.out.println(sql);

        List test = em.createNativeQuery(sql).getResultList();

        return test;
    }
}

The invoke code is that:

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

    @Autowired
    private SomeDao dao;

    @RequestMapping("/test2")
    public HttpEntity test2() {
        var l = dao.listFoodMoneyDateOfPayment(12, "food_payment", "payment_application");
        System.out.println(l.getClass());
        System.out.println(JSON.toJSONString(l));
        return ResultBean.success();
    }
}

And it works well.
But you should check the arguments passed in.