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3.iBatis删除操作教程

发布制作：admin　　发布日期：2011/6/8
我希望通过上面的例子，你能完全懂得如何向数据库执行插入或者查询操作.所以在本例中你将学习到如何通过iBatis在数据库中删除数据.所以你需要分析代码并清楚的理解在这些代码里到底发生了什么.然而你绝对不需要再创建一个不同的数据库,虽然你知道我们使用上一个MySQL作为数据库而且你已经知道了我们的表名是Contact.但你可以选择是使用这个数据库还是再创建一个,这都由你决定!你唯一需要确定的就是你定义的表名是正确的,否则将会产生Bug.如果你从本iBatis的开始学下来的,那么你是不需要修改代码的.仅仅将给定的代码拷贝到文件夹并执行,最终删除数据库表中的数据.
正如我之前提到的,在iBatis的本章,我们将要从Ctract表中删除记录,我们使用MySQL的数据库"vin"
我们的Contact.java和SqlMapConfig.xm是与上一个例子中的是一样的.
Contact.java

public class Contact {

 
? private String firstName; 
??private String lastName;?? 
??private String email;? 
??private int id;
?
? public Contact() {}
? 
??public Contact(
??? String firstName,
??? String lastName,
??? String email) {
??? this.firstName = firstName;
??? this.lastName = lastName;
??? this.email = email;
??? }
? 
??public String getEmail() {
??? return email;
? }
? public void setEmail(String email) {
??? this.email = email;
? }
? public String getFirstName() {
??? return firstName;
? }
? public void setFirstName(String firstName) {
??? this.firstName = firstName;
? }
? public int getId() {
??? return id;
? }
? public void setId(int id) {
??? this.id = id;
? }
? public String getLastName() {
??? return lastName;
? }
? public void setLastName(String lastName) {
??? this.lastName = lastName;
? } 
}

SqlMapConfig.xml

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

 
<!DOCTYPE sqlMapConfig
PUBLIC "-//ibatis.apache.org//DTD SQL Map Config 2.0//EN"
"http://ibatis.apache.org/dtd/sql-map-config-2.dtd">
?
<sqlMapConfig>
?? <settings useStatementNamespaces="true"/>
???? <transactionManager type="JDBC">
??????? <dataSource type="SIMPLE">
????????? <property name="JDBC.Driver" value="com.mysql.jdbc.Driver"/>
????????? <property name="JDBC.ConnectionURL"
?????????????? value="jdbc:mysql://192.168.10.112:3306/vin"/>
????????? <property name="JDBC.Username" value="root"/>
????????? <property name="JDBC.Password" value="root"/>
??????? </dataSource>
????? </transactionManager>
???? <sqlMap resource="Contact.xml"/> 
</sqlMapConfig>

在Contract.xml文件中我们使用<delete>标签删除Contract表中的全部记录.

<delete id="deleteAll" parameterClass="Contact">

 
???????? delete from Contact
</delete>

上面几行代码删除了Contract表中的所有记录,这里定义的id"deleteAll"会在IbatisDeletion类中执行数据库的查询操作.

Contact.xml

<?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="Contact">
<!--- Delete data from Contact table --> 
<delete id="deleteAll" parameterClass="Contact">
???????? delete from Contact
</delete> 
<!--- Showing all data of table --> 
<select id="getAll" resultClass="Contact">
?????? select * from contact
</select>
</sqlMap>

我们需要引入下面的包 :

com.ibatis.common.resources
com.ibatis.sqlmap.client
SQL映射所需的类和接口 :

Reader reader = Resources.getResourceAsReader("SqlMapConfig.xml");

 
??? SqlMapClient sqlMap = 
????SqlMapClientBuilder.buildSqlMapClient(reader);

上面的代码能从"SqlMapConfig.xml"中读取配置信息, IbatisDeletion.java的代码如下 :

IbatisDeletion.java

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 IbatisDeletion{
? public static void main(String[] args)
??? throws IOException,SQLException{
??? Reader reader = Resources.getResourceAsReader("SqlMapConfig.xml");
??? SqlMapClient sqlMap = 
????SqlMapClientBuilder.buildSqlMapClient(reader);
???? //Deleting all records from contacts
??? System.out.println("*-- Deleting informations from Contact------*");
??? Contact contct=new Contact();
??? sqlMap.delete("Contact.deleteAll",contct);
??? System.out.println("|Deleted Record Successfully ");
??? System.out.println("All Contacts");
????? List<Contact> contacts = (List<Contact>)
??????? sqlMap.queryForList("Contact.getAll",null);
??????? Contact contact = null;
????? for (Contact c : contacts) {
????? System.out.print("? " + c.getId());
 ???????System.out.print("? " + c.getFirstName());
????? System.out.print("? " + c.getLastName());
????? System.out.print("? " + c.getEmail());
??????? contact = c; 
??????System.out.println("");
??? }
??? System.out.println("============================================");
????? }??? 
}

按照如下步骤执行本例 :

创建Contact.xml和SqlMapConfig.xml
创建Contract.java并将其编译
创建IbatisDeletion.java并将其编译
执行IbatisDeletion你将会在你的命令提示符中得到如下输出 :