iBATIS的更新操作

我們討論，在最后一章，如何在使用iBATIS表執(zhí)行讀操作。本章介紹了如何更新使用iBATIS表中的記錄。

我們?cè)贛ySQL中下EMPLOYEE表 -

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)
);

此表只有一個(gè)記錄如下 -

mysql> select * from EMPLOYEE;
+----+------------+-----------+--------+
| id | first_name | last_name | salary |
+----+------------+-----------+--------+
|  1 | Zara       | Ali       |   5000 |
+----+------------+-----------+--------+
1 row in set (0.00 sec)

員工PO??JO類

要執(zhí)行UDPATE操作，你就需要修改Employee.java文件內(nèi)容如下 -

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;
   }

   /* Here are the required method definitions */
   public int getId() {
      return id;
   }
	
   public void setId(int id) {
      this.id = id;
   }
	
   public String getFirstName() {
      return first_name;
   }
	
   public void setFirstName(String fname) {
      this.first_name = fname;
   }
	
   public String getLastName() {
      return last_name;
   }
   public void setlastName(String lname) {
      this.last_name = lname;
   }
	
   public int getSalary() {
      return salary;
   }
	
   public void setSalary(int salary) {
      this.salary = salary;
   }

} /* End of Employee */

Employee.xml文件

要定義使用iBATIS SQL映射語(yǔ)句中，我們將增加<更新>在Employee.xml這個(gè)標(biāo)簽定義標(biāo)記內(nèi)，我們將定義將在IbatisUpdate.java文件中，用于對(duì)數(shù)據(jù)庫(kù)執(zhí)行SQL UPDATE查詢的“身份證”。

<?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>

   <select id="getAll" resultClass="Employee">
      SELECT * FROM EMPLOYEE
   </select>

   <update id="update" parameterClass="Employee">
      UPDATE EMPLOYEE
      SET    first_name = #first_name#
      WHERE  id = #id#
   </update>
	
</sqlMap>

IbatisUpdate.java文件

此文件具有應(yīng)用程序級(jí)別的邏輯來更新記錄到Employee表 -

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 IbatisUpdate{
   public static void main(String[] args)
   throws IOException,SQLException{
      Reader rd = Resources.getResourceAsReader("SqlMapConfig.xml");
      SqlMapClient smc = SqlMapClientBuilder.buildSqlMapClient(rd);

      /* This would update one record in Employee table. */
      System.out.println("Going to update record.....");
      Employee rec = new Employee();
      rec.setId(1);
      rec.setFirstName( "Roma");
      smc.update("Employee.update", rec );
      System.out.println("Record updated Successfully ");

      System.out.println("Going to read records.....");
      List <Employee> ems = (List<Employee>)
         smc.queryForList("Employee.getAll", null);
      Employee em = null;
		
      for (Employee e : ems) {
         System.out.print("  " + e.getId());
         System.out.print("  " + e.getFirstName());
         System.out.print("  " + e.getLastName());
         System.out.print("  " + e.getSalary());
         em = e; 
         System.out.println("");
      }    

      System.out.println("Records Read Successfully ");
   }
} 

編譯和運(yùn)行

以下是編譯并運(yùn)行上述軟件的步驟。請(qǐng)確保您已設(shè)置PATH和CLASSPATH在進(jìn)行適當(dāng)?shù)木幾g和執(zhí)行之前。

• 創(chuàng)建Employee.xml如上所示。
• 創(chuàng)建Employee.java如上圖所示，并對(duì)其進(jìn)行編譯。
• 創(chuàng)建IbatisUpdate.java如上圖所示，并對(duì)其進(jìn)行編譯。
• 執(zhí)行IbatisUpdate二進(jìn)制運(yùn)行程序。

你會(huì)得到下面的結(jié)果，并創(chuàng)下會(huì)在EMPLOYEE表進(jìn)行更新和后，同樣會(huì)記錄從EMPLOYEE表中讀取。

Going to update record.....
Record updated Successfully
Going to read records.....
   1  Roma  Ali  5000
Records Read Successfully