如何在 Spring Boot 中更新表列？

Question

我正在尝试使用 @PostMapping 更新 Mysql 中的列。

实体表有5列

customer_id, customer_name, total_amount, amount_paid, amount_debt

我们为customer_name, total_amount, amount_paid 提供参数。

amount_debt 将计算为 amount_total - amount_paid 并写回每个 POST 的 amount_debt 列。

等价的SQL好像是

update emi_details 
set amount_debt = amount_total - amount_paid;

我试过了，使用

getAmount_debt() { return amount_total - amount_paid; }
setAmount_debt(Integer amount_debt) { this.amount_debt = amount_total - amount_debt; }

实体类中的方法。

但是，在POST 请求中，我似乎需要提供"amount_debt": 0 参数，否则它不会被写入MySql。

当我尝试删除 get 和 set 方法并在构造函数中执行 minus，然后在没有 "amount_debt": 0 的情况下执行 POST 请求时，它显示 amount_debt 具有响应值，但没有amount_debt 列中的值。

看来，我之前可能需要在@PostMapping里面写一些@Query

return emiDetailsRepository.save(emiDetails);

但我不确定。

请指导

我尝试的事情如下：

1. 实体 - EmiDetails.java

@Entity
@Table(name = "emi_details")
public class EmiDetails {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer customer_id;
    
    @Column(name = "customer_name")
    private String customer_name;
    
    @Column(name = "amount_total")
    private Integer amount_total;
    
    @Column(name = "amount_paid")
    private Integer amount_paid;
    
    @Column(name = "amount_debt")
    private Integer amount_debt;;

    public EmiDetails() {}
    
    public EmiDetails(String customer_name, Integer amount_total, Integer amount_paid, Integer amount_debt) {
        super();
        this.customer_name = customer_name;
        this.amount_total = amount_total;
        this.amount_paid = amount_paid;
        this.amount_debt = amount_total - amount_paid;
    }

    public Integer getCustomer_id() {
        return customer_id;
    }

    public void setCustomer_id(Integer customer_id) {
        this.customer_id = customer_id;
    }

    public String getCustomer_name() {
        return customer_name;
    }

    public void setCustomer_name(String customer_name) {
        this.customer_name = customer_name;
    }

    public Integer getAmount_total() {
        return amount_total;
    }

    public void setAmount_total(Integer amount_total) {
        this.amount_total = amount_total;
    }

    public Integer getAmount_paid() {
        return amount_paid;
    }

    public void setAmount_paid(Integer amount_paid) {
        this.amount_paid = amount_paid;
    }

    public Integer getAmount_debt() {
        return amount_total - amount_paid;
    }

    public void setAmount_debt(Integer amount_debt) {
        this.amount_debt = amount_total - amount_debt;
    }   
}

1. 存储库EmiDetailsRepository.java

public interface EmiDetailsRepository extends JpaRepository<EmiDetails, Integer> {}

1. 控制器 - EmiDetailsContoller.java

@RestController
@RequestMapping("/api/v1")
public class EmiDetailsContoller {
    @Autowired
    private EmiDetailsRepository emiDetailsRepository;
    
    //get all data
    @GetMapping("/emi_details")
    public List<EmiDetails> getAllEmiDetails() {
        return emiDetailsRepository.findAll();
    }
    
    //post data
    @PostMapping("/emi_details")
    public EmiDetails createEmiRecord(@RequestBody EmiDetails emiDetails) {
        return emiDetailsRepository.save(emiDetails);
    }
}

4. POST 请求 - 在每一列中写入数据

{
    "customer_name": "Sandeep Roy",
    "amount_total": 75,
    "amount_paid": 8,
    "amount_debt": 0
}

5. POST 请求 - 写入数据但在 amount_debt 列中

{
  "customer_name": "Sandeep Roy",
  "amount_total": 75,
  "amount_paid": 8,
}

很抱歉写了关于问题本身的所有内容，还没有尝试过 Heroku。

Answer 1

简答

计算createEmiRecord 方法中的债务金额。

只需将您的 @PostMapping 方法更新为以下代码

@PostMapping("/emi_details")
public EmiDetails createEmiRecord(@RequestBody EmiDetails emiDetails) {
    
    //Calculate your debt here using the values in the provided emiDetails
    
    return emiDetailsRepository.save(emiDetails);
}

长答案

首先修复您的实体类。实体类是普通的 POJO，不应该有任何业务逻辑。

@Entity
@Table(name = "emi_details")
public class EmiDetails {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer customer_id;
    
    @Column(name = "customer_name")
    private String customer_name;
    
    @Column(name = "amount_total")
    private Integer amount_total;
    
    @Column(name = "amount_paid")
    private Integer amount_paid;
    
    @Column(name = "amount_debt")
    private Integer amount_debt;

    .....SETTERS AND GETTERS

}

将您的 createEmiRecord 方法更新为以下内容

@PostMapping("/emi_details")
public EmiDetails createEmiRecord(@RequestBody EmiDetails emiDetails) {
    
    //Calculate Amount debt here
    Integer amount_debt = emiDetails.getAmount_total() - emiDetails.getAmount_paid();
    
    emiDetails.setAmount_debt(amount_debt);
    
    return emiDetailsRepository.save(emiDetails);

}