对任何数据库程序来说,添加,更新,删除都是十分常见且必要的特性.在该教程里我们已经讲解了使用iBatis在Java中进行插入和删除操作,现在本章将讲述如何使用iBatis在数据表中更新数据.在iBatis中执行一条更新语句是非常简单的.为了更新数据你得在SQL映射文件"Contact.xml"中添加SQL的update语句.
iBatis更新语句例子 :
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>
iBatis更新查询
在我们的例子中,我们通过参数中指定的id更新了表中的数据,因此对于"id"我们将"parameterClass"的属性值分配为"long".
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">
<!--- Showing all data of table -->
???????? <select id="getAll" resultClass="Contact">
?????????????? select * from contact
??????? </select>
<!--- Update data of Contact table -->
?<update id="updateById" parameterClass="long">
?????? update Contact
??????????????????set
??????????????????lastName = 'Raghuwanshi'
???????????????????????????? where
????????????????????????????????????? id=#id#
</update>
</sqlMap>
现在我们可以在Java程序中通过如下代码执行更新操作了 :
sqlMap.update("Contact.updateById",contactId);
IbatisUpdate.java代码如下 :
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 reader = Resources.getResourceAsReader(
??????????????????? "SqlMapConfig.xml"
? ??????????????????);
??? SqlMapClient sqlMap = SqlMapClientBuilder.buildSqlMapClient(reader);
????? //Updating one record of contact
??? System.out.println("*---- Updating informations of Contact -----*");
??? Contact contct=new Contact();
??? long contactId=1;
??? sqlMap.update("Contact.updateById",contactId);
????? System.out.println("|Updated 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("============================================");
?? }???
}
为了执行update的例子,遵照如下步骤 :
创建Contact.java和SqlMapConfig.xml
编译Contact.java
创建Contact.xml
创建IbatisUpdate.java并将其编译