MYBATIS - Delete Operation

This chapter describes how to delete records from a table using MyBatis.

We have the following STUDENT table in MySQL −

CREATE TABLE details.student(
   ID int(10) NOT NULL AUTO_INCREMENT,
   NAME varchar(100) NOT NULL,
   BRANCH varchar(255) NOT NULL,
   PERCENTAGE int(3) NOT NULL,
   PHONE int(11) NOT NULL,
   EMAIL varchar(255) NOT NULL,
   PRIMARY KEY (`ID`)
);

Assume, this table has two records as −

mysql> select * from STUDENT;
+----+----------+--------+------------+-----------+----------------------+
| ID |  NAME    | BRANCH | PERCENTAGE |  PHONE    |       EMAIL          |
+----+----------+--------+------------+-----------+----------------------+
| 1  | Mohammad |   It   |     80     | 900000000 | mohamad123@yahoo.com |
| 2  | shyam    |   It   |     75     | 984800000 | shyam@gmail.com      |
+----+----------+--------+------------+-----------+----------------------+
2 rows in set (0.00 sec)

STUDENT POJO Class

To perform delete operation, you do not need to modify Student.java file. Let us keep it as it was in the last chapter.

public class Student {

   private int id;
   private String name;
   private String branch;
   private int percentage;
   private int phone;
   private String email;

   public Student(int id, String name, String branch, int percentage, int phone, String email) {
      super();
      this.id = id;
      this.name = name;
      this.setBranch(branch);
      this.setPercentage(percentage);
      this.phone = phone;
      this.email = email;
   }
	
   public Student() {}

   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 int getPhone() {
      return phone;
   }
	
   public void setPhone(int phone) {
      this.phone = phone;
   }
	
   public String getEmail() {
      return email;
   }
	
   public void setEmail(String email) {
      this.email = email;
   }

   public String getBranch() {
      return branch;
   }

   public void setBranch(String branch) {
      this.branch = branch;
   }

   public int getPercentage() {
      return percentage;
   }

   public void setPercentage(int percentage) {
      this.percentage = percentage;
   }
	
   public String toString(){
      StringBuilder sb = new StringBuilder();
		
      sb.append("Id = ").append(id).append(" - ");
      sb.append("Name = ").append(name).append(" - ");
      sb.append("Branch = ").append(branch).append(" - ");
      sb.append("Percentage = ").append(percentage).append(" - ");
      sb.append("Phone = ").append(phone).append(" - ");
      sb.append("Email = ").append(email);
		
      return sb.toString();
   }
	
}

Student.xml File

To define SQL mapping statement using MyBatis, we would use <delete> tag in Student.xml and inside this tag definition, we would define an "id" which will be used in mybatisDelete.java file for executing SQL DELETE query on database.

<?xml version = "1.0" encoding = "UTF-8"?>

<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
	
<mapper namespace = "Student">	
   <resultMap id = "result" type = "Student">
      <result property = "id" column = "ID"/>	    
   </resultMap>
	
   <delete id = "deleteById" parameterType = "int">
      DELETE from STUDENT WHERE ID = #{id};
   </delete>
    	
</mapper>

MyBatisDelete.java File

This file has application level logic to delete records from the Student table −

import java.io.IOException;
import java.io.Reader;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class mybatisDelete { 

   public static void main(String args[]) throws IOException{
      
      Reader reader = Resources.getResourceAsReader("SqlMapConfig.xml");
      SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);		
      SqlSession session = sqlSessionFactory.openSession(); 
	  
      //Delete operation
      session.delete("Student.deleteById", 2);     
      session.commit();
      session.close();      
      System.out.println("Record deleted successfully");
			
   }
   
}

Compilation and Run

Here are the steps to compile and run mybatisDelete.java. Make sure, you have set PATH and CLASSPATH appropriately before proceeding for compilation and execution.

  • Create Student.xml as shown above.

  • Create SqlMapConfig.xml as shown in the MYBATIS - Configuration XML chapter of this tutorial.

  • Create Student.java as shown above and compile it.

  • Create mybatisDelete.java as shown above and compile it.

  • Execute mybatisDelete binary to run the program.

You would get the following result, and a record with ID = 1 would be deleted from the STUDENT.

Records Read Successfully

If you check the STUDENT table, it should display the following result −

mysql> select * from student;
+----+----------+--------+------------+----------+----------------------+
| ID |   NAME   | BRANCH | PERCENTAGE |  PHONE   |        EMAIL         |
+----+----------+--------+------------+----------+----------------------+
| 1  | Mohammad |   It   |    80      | 90000000 | mohamad123@yahoo.com |
+----+----------+--------+------------+----------+----------------------+
1 row in set (0.00 sec)
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