Use Equal Operator in JEntity Framework

Create Database

Create a database named mydb. This database have product table as below:

--
-- Table structure for table `product`
--

CREATE TABLE `product` (
  `id` int(11) IDENTITY(1,1) NOT NULL PRIMARY KEY,
  `name` varchar(250) COLLATE utf8_unicode_ci NOT NULL,
  `price` decimal(10,1) DEFAULT NULL,
  `quantity` int(11) DEFAULT NULL,
  `description` text COLLATE utf8_unicode_ci NOT NULL,
  `status` tinyint(1) DEFAULT NULL,
  `dateCreated` datetime NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

--
-- Dumping data for table `product`
--

INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `status`, `dateCreated`) VALUES
('Mobile 1', '2.0', 2, 'Description of Mobile 1', 0, '2017-09-12 00:00:00'),
('Mobile 2', '1.0', 5, 'Description of Mobile 2', 0, '2018-11-21 00:00:00'),
('Mobile 3', '3.4', 2, 'Description of Mobile 3', 0, '2018-09-24 00:00:00'),
('Laptop 1', '5.5', 17, 'Description of Laptop 1', 1, '2018-11-09 00:00:00'),
('Laptop 2', '7.0', 8, 'Description of Laptop 2', 0, '2017-10-26 00:00:00'),
('Laptop 4', '3.0', 11, 'Description of Laptop 4', 0, '2018-10-11 00:00:00'),
('Computer 1', '41.5', 6, 'Description of Computer 1', 1, '2017-11-27 00:00:00'),
('Computer 2', '7.0', 2, 'Description of Computer 2', 1, '2018-09-21 00:00:00');

Structure of Product Table

Data of Product Table

Database Configuration

Create new json file named appsettings.json in the classpath of your project

{
  "connectionString": {
    "url": "jdbc:mysql://localhost:3306/mydb",
    "username": "root",
    "password": "123456"
  }
}

Create Entity

Create new package named entities. In this package, create new java class named Product.java as below:

package entitites;

import java.io.Serializable;
import java.math.BigDecimal;
import java.time.LocalDate;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Table(name = "product")
public class Product implements Serializable {

	@Id
	@GeneratedValue
	private int id;

	private String name;

	private BigDecimal price;

	private int quantity;

	private String description;

	private boolean status;

	private LocalDate dateCreated;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

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

	public BigDecimal getPrice() {
		return price;
	}

	public void setPrice(BigDecimal price) {
		this.price = price;
	}

	public int getQuantity() {
		return quantity;
	}

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

	public String getDescription() {
		return description;
	}

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

	public boolean isStatus() {
		return status;
	}

	public void setStatus(boolean status) {
		this.status = status;
	}

	public LocalDate getDateCreated() {
		return dateCreated;
	}

	public void setDateCreated(LocalDate dateCreated) {
		this.dateCreated = dateCreated;
	}

}

Create Database Context

Create new package named models. In this package, create new java class named MyDemoContext.java as below:

package models;

import entitites.Product;
import jentityframework.DbSet;

public class MyDemoContext  {

	public DbSet Products;
	
	public MyDemoContext() {
		Products = new DbSet(Product.class);
	}
	
}

Run Application

package demo;

import java.util.List;
import entities.Product;
import models.MyDBContext;

public class Demo {

	public static void main(String[] args) {

		MyDBContext db = new MyDBContext();
		List products = db.Products.Where(p -> p.isStatus() == true).toList();
		for (Product product : products) {
			System.out.println("id: " + product.getId());
			System.out.println("name: " + product.getName());
			System.out.println("price: " + product.getPrice());
			System.out.println("status: " + product.isStatus());
			System.out.println("date: " + product.getDateCreated());
			System.out.println("====================");
		}

	}

}

Output

id: 4
name: Laptop 1
price: 5.5
status: true
date: 2018-11-09
====================
id: 12
name: Computer 1
price: 41.5
status: true
date: 2017-11-27
====================
id: 13
name: Computer 2
price: 7.0
status: true
date: 2018-09-21
====================