This topic is about iBATIS – Create Operation.
To perform any Create, Read, Update, and Delete (CRUD) operation using iBATIS, you would need to create a Plain Old Java Objects (POJO) class corresponding to the table. This class describes the objects that will “model” database table rows.
The POJO class would have implementation for all the methods required to perform desired operations.
Let us assume we have the following EMPLOYEE table in MySQL −
CREATE TABLE EMPLOYEE ( id INT NOT NULL auto_increment, first_name VARCHAR(20) default NULL, last_name VARCHAR(20) default NULL, salary INT default NULL, PRIMARY KEY (id) );
Employee POJO Class
We would create an Employee class in Employee.java file as follows −
public class Employee {
private int id;
private String first_name;
private String last_name;
private int salary;
/* Define constructors for the Employee class. */
public Employee() {}
public Employee(String fname, String lname, int salary) {
this.first_name = fname;
this.last_name = lname;
this.salary = salary;
}
} /* End of Employee */
You can define methods to set individual fields in the table. The next chapter explains how to get the values of individual fields.
Employee.xml File
To define SQL mapping statement using iBATIS, we would use <insert> tag and inside this tag definition, we would define an “id” which will be used in IbatisInsert.java file for executing SQL INSERT query on database.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sqlMap PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN" "http://ibatis.apache.org/dtd/sql-map-2.dtd">
<sqlMap namespace="Employee">
<insert id="insert" parameterClass="Employee">
insert into EMPLOYEE(first_name, last_name, salary)
values (#first_name#, #last_name#, #salary#)
<selectKey resultClass="int" keyProperty="id">
select last_insert_id() as id
</selectKey>
</insert>
</sqlMap>
Here parameterClass − could take a value as string, int, float, double, or any class object based on requirement. In this example, we would pass Employee object as a parameter while calling insert method of SqlMap class.
If your database table uses an IDENTITY, AUTO_INCREMENT, or SERIAL column or you have defined a SEQUENCE/GENERATOR, you can use the <selectKey> element in an <insert> statement to use or return that database-generated value.
IbatisInsert.java File
This file would have application level logic to insert records in the Employee table −
import com.ibatis.common.resources.Resources;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;
import java.io.*;
import java.sql.SQLException;
import java.util.*;
public class IbatisInsert{
public static void main(String[] args)throws IOException,SQLException{
Reader rd = Resources.getResourceAsReader("SqlMapConfig.xml");
SqlMapClient smc = SqlMapClientBuilder.buildSqlMapClient(rd);
/* This would insert one record in Employee table. */
System.out.println("Going to insert record.....");
Employee em = new Employee("Zara", "Ali", 5000);
smc.insert("Employee.insert", em);
System.out.println("Record Inserted Successfully ");
}
}
Compilation and Run
Here are the steps to compile and run the above mentioned software. Make sure you have set PATH and CLASSPATH appropriately before proceeding for compilation and execution.
- Create Employee.xml as shown above.
- Create Employee.java as shown above and compile it.
- Create IbatisInsert.java as shown above and compile it.
- Execute IbatisInsert binary to run the program.
You would get the following result, and a record would be created in the EMPLOYEE table.
$java IbatisInsert Going to insert record..... Record Inserted Successfully
If you check the EMPLOYEE table, it should display the following result −
mysql> select * from EMPLOYEE; +----+------------+-----------+--------+ | id | first_name | last_name | salary | +----+------------+-----------+--------+ | 1 | Zara | Ali | 5000 | +----+------------+-----------+--------+ 1 row in set (0.00 sec)
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