One Field is not getting saved to the database, always returns as 0.0

Question

Im trying to save product entity in postgres table, and if i send request from postman, it returns sved object, but MRP field is always 0.0

Entity class:

package com.acms.models;

import java.time.Instant;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "product")
public class Product {
    @Id
    @Column(name = "productid")
    private String productId;
    @Column(name = "timestamp")
    private long timeStamp;
    private String description;
    private String name;
    @Column(name = "mrp")
    private double mRP;
    private int quantity;
    private double promotion;

    public Product() {
        super();
        long epochTime = Instant.now().getEpochSecond();
        this.timeStamp = epochTime;
    }

    public String getProductId() {
        return productId;
    }

    public void setProductId(String productId) {
        this.productId = productId;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getMRP() {
        return mRP;
    }

    public void setMRP(double mRP) {
        this.mRP = mRP;
    }

    public int getQuantity() {
        return quantity;
    }

    public void setQuantity(int quantity) {
        this.quantity = quantity;
    }

    public double getPromotion() {
        return promotion;
    }

    public void setPromotion(double promotion) {
        this.promotion = promotion;
    }

    @Override
    public String toString() {
        return "Product [productId=" + productId + ", timeStamp=" + timeStamp + ", description=" + description
                + ", name=" + name + ", MRP=" + mRP + ", quantity=" + quantity + ", promotion=" + promotion + "]";
    }
}

Controller:

@PostMapping("/product/save")
    public Product postDataToProductTable(@RequestBody Product product) {
        return this.productService.postDataToProductTable(product);
    }

Service:

public Product postDataToProductTable(Product product) {
        return this.productRepository.save(product);
    }

Request sent with url and object:

http://localhost:8080/product/save
{
    "productId":"p106",
    "description":"butter",
    "name":"amul",
    "mRP":"200",
    "quantity":"8",
    "promotion":"5.0"
}

Object returned:

{
    "productId": "p106",
    "description": "butter",
    "name": "amul",
    "quantity": 8,
    "promotion": 5.0,
    "mrp": 0.0
}

notice how above, the mrp is returned as 0.0, but all other fields are fine.

Table in postgres:

CREATE TABLE product (
    serialNumber SERIAL,
    productID VARCHAR(50) NOT NULL,
    timeStamp bigint NOT NULL,
    description VARCHAR(50),
    name VARCHAR(50) NOT NULL,
    MRP NUMERIC NOT NULL,
    quantity int NOT NULL,
    promotion NUMERIC,
    PRIMARY KEY(productID),
    UNIQUE(productID, timeStamp)
);

yes, its getting saved as default value i think, i dont know why its not mapping to mRP — Madhumita Ganga S, May 02 '20 at 13:23
I think it is beacuse the annotation say column name `mrp` (lover case) the database says `MRP´ aupper case). — Jens, May 02 '20 at 13:24
no, postgres converts everything to lowercase, even if i change mrp to MRP in the entity class, it still returning 0 and entering 0 in database. — Madhumita Ganga S, May 02 '20 at 13:27
according to that, shouldn't @Column(name = "productid") be @Column(name = "productId") ? that is saving fine, — Madhumita Ganga S, May 02 '20 at 13:28
@MadhumitaGangaS, Can you print your product object before calling the same method and see if values are properly set to the object. — Sreenath Reddy, May 02 '20 at 13:32
Product [productId=p110, timeStamp=1588426591, description=butter, name=amul, MRP=0.0, quantity=8, promotion=5.0] — Madhumita Ganga S, May 02 '20 at 13:36
Use proper type with column definition see here https://www.service-architecture.com/articles/database/mapping_sql_and_java_data_types.html — Eklavya, May 02 '20 at 13:39
1) Can you send mRP as 200.00 and see if any luck and also tryy changing mRP variable to mrp and see, I am suspecting while setting mrp value it couldn't find appropriate setter method — Sreenath Reddy, May 02 '20 at 13:47

Sebastiaan van den Broek · Accepted Answer · 2020-05-02T14:01:38.820

1

Possibly because your JSON request sends mRP as a String type, but in your model it's defined as a double. Lose the "" around mRP's value in the JSON request and see if that helps.

Another option is that you defined this type as numeric in the database, but in the model it's a double. In my experience I would prefer to use a BigDecimal to map to a numeric field in postgres. But if it must be a double in your model then why not use that as a type in the database as well? Not everything that can be saved in a numeric field can actually be represented in a Java double.

Postgres data types: https://www.postgresql.org/docs/9.1/datatype-numeric.html

Also (from comments discussion) inconsistent casing between the Json and the field name in the model and could be causing issues if using Spring Data JPA/Spring MVC.

edited May 02 '20 at 14:01

answered May 02 '20 at 13:32

Sebastiaan van den Broek

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doesn't help :/ – Madhumita Ganga S May 02 '20 at 13:35
How come promotion is working, then? that is also numeric and double. – Madhumita Ganga S May 02 '20 at 13:44
@MadhumitaGangaS you're right, that is strange. Still I would recommend choosing the recomended data types. If that doesn't help, you should turn on sql logging, in particular set the `org.hibernate.SQL` lognode to `debug`, it should show you which updates and which queries are being done for this request. – Sebastiaan van den Broek May 02 '20 at 13:47
i displayed the object before calling save, Product [productId=p110, timeStamp=1588426591, description=butter, name=amul, MRP=0.0, quantity=8, promotion=5.0] – Madhumita Ganga S May 02 '20 at 13:50
@MadhumitaGangaS Ok, so it's not even set on insertion. I would try to use a consistent spelling/casing of MRP, because now it's sometimes uppercased, sometimes lowercased and then in the json it only has the m lowercase. That might be an issue for Spring Data JPA. – Sebastiaan van den Broek May 02 '20 at 13:51
its not saving in the object also – Madhumita Ganga S May 02 '20 at 13:52
@MadhumitaGangaS ok so what if the field is called `mrp` or `MRP` in the JSON? Still the same result? – Sebastiaan van den Broek May 02 '20 at 13:53
changed mRP to mrp and now its working! no clue why it didnt work before. – Madhumita Ganga S May 02 '20 at 13:58
Probably the Jackson objectmapper that Spring MVC uses to map the JSON to the model is case sensitive. There are probably some settings you could tweak for that, although I wouldn't touch it myself. – Sebastiaan van den Broek May 02 '20 at 14:04

One Field is not getting saved to the database, always returns as 0.0

1 Answers1