分享知識-快樂自己：Mybatis 基礎動態語句
阿新 • • 發佈：2018-12-15
目錄：
User：
package mlq.bean;
/**
* 使用者實體類
*/
public class User {
private Integer uId;
private String userName;
private String userPwd;
private String realName;
public User(Integer uId, String userName, String userPwd, String realName) {
this.uId = uId;
this.userName = userName;
UserMappers：
package mlq.Mapper;
import mlq.bean.User;
import org.apache.ibatis.annotations.Param;
import java.util.List;
import java.util.Map;
/**
* 使用者介面
*/
public interface UserMappers {
/**
* 查詢使用者資訊
*/
public List<User> userAllList(User user);
MyBatis.xml：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<!---->
<configuration>
<!--引入properties檔案-->
<properties resource="DatabaseConfig.properties" />
<!--設定類別名-->
<typeAliases>
<package name ="mlq.bean" />
</typeAliases>
<!--設定Mybatis執行環境-->
<environments default="mysql"><!--default找到環境的id，只能用一個-->
<environment id="mysql"><!--可以定義多個環境-->
<transactionManager type="JDBC"/><!--後續事務的管理 統一交給spring容器-->
<dataSource type="POOLED"><!--資料來源 Tomcat：JNDI Mybatis：POOLED-->
<property name="driver" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="mapper/UserMapper.xml"/>
</mappers>
</configuration>
MyBatisTool：
package mlq.util;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.IOException;
import java.io.Reader;
/**
* 獲取連線物件工具類
*/
public class MyBatisTool {
//建立私有構造
private MyBatisTool(){}
//SQLSessionFactory 簡單的理解就是建立SQLSession 例項的工廠。
private final static SqlSessionFactory sqlSessionFactory;
//靜態程式碼塊初始化sqlSessionFactory物件
static
{
//獲取Mybatis.xml核心配置檔案路徑
String path="MyBatis.xml";
Reader reader=null;
try {
//將檔案資訊讀取到記憶體中
reader = Resources.getResourceAsReader(path);
} catch (IOException e) {
e.printStackTrace();
}
//建立例項
sqlSessionFactory=new SqlSessionFactoryBuilder().build(reader);
}
/**
* 獲取工廠函式SQLSessionFactory
* @return
*/
public static SqlSessionFactory getSqlSessionFactory() { return sqlSessionFactory; }
/**
* 獲取SqlSession連線物件
* @return
*/
public static SqlSession getSqlSession(){return sqlSessionFactory.openSession();}
/**
* 關閉連線物件
* @param sqlSession
*/
public static void closeSqlsession(SqlSession sqlSession){
if (sqlSession!=null)
{
sqlSession.close();
}
}
}
UserMapper.xml：
<?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="mlq.Mapper.UserMappers">
<!--使用Where標籤實現動態SQL拼接-->
<select id="userAllListTow" parameterType="User" resultType="User">
SELECT * FROM `user` WHERE 1=1
<if test="userName!=null and userName!=''">
AND `userName`=#{userName}
</if>
<if test="userPwd!=null and userPwd!=''">
AND `userPwd`=#{userPwd}
</if>
<if test="uId!=null and uId!=''">
AND `uId`=#{uId}
</if>
</select>
<!--使用Where標籤實現動態SQL拼接-->
<select id="userAllList" parameterType="User" resultType="User">
SELECT * FROM `user`
<where>
<if test="userName!=null and userName!=''">
AND `userName`=#{userName}
</if>
<if test="userPwd!=null and userPwd!=''">
AND `userPwd`=#{userPwd}
</if>
<if test="uId!=null and uId!=''">
AND `uId`=#{uId}
</if>
</where>
</select>
<!--使用SET標籤更新資料:說明此番操作有漏洞。逗號位置不明確：建議使用下述方式-->
<update id="updUser" parameterType="User">
UPDATE `user`
<set>
<if test="userName!=null and userName!=''">
`userName`=#{userName},
</if>
<if test="userPwd!=null and userPwd!=''">
`userPwd`=#{userPwd},
</if>
<if test="realName!=null and realName!=''">
`realName`=#{realName},
</if>
</set>
<where>
`uId`=#{uId}
</where>
</update>
<update id="updUserTow" parameterType="User">
UPDATE `user`
<trim prefix="set" suffixOverrides="," suffix="`uId`=#{uId}">
<if test="userName!=null and userName!=''">
`userName`=#{userName},
</if>
<if test="userPwd!=null and userPwd!=''">
`userPwd`=#{userPwd},
</if>
<if test="realName!=null and realName!=''">
`realName`=#{realName},
</if>
</trim>
</update>
<!--公用SQL片段-->
<sql id="cols"> SELECT * FROM `user`</sql>
<!--使用choose方式判斷：相當於switch結構-->
<select id="userAllListChoose" parameterType="User" resultType="User">
<include refid="cols"/>
<where>
<choose>
<when test="userName!=null and userName!=''">
AND `userName`=#{userName}
</when>
<when test="userPwd!=null and userPwd!=''">
AND `userPwd`=#{userPwd}
</when>
<otherwise>
AND `uId`=#{uId}
</otherwise>
</choose>
</where>
</select>
<!--使用陣列入參，Foreach遍歷-->
<select id="userArrays" resultType="User">
<include refid="cols"/>
<trim prefix="where `uId` in">
<if test="array.length>0">
<foreach item="temp" collection="array" open="(" close=")" separator=",">
#{temp}
</foreach>
</if>
</trim>
</select>
<!--使用List普通入參，Foreach遍歷-->
<select id="userListForeach" resultType="User">
<include refid="cols"/>
<trim prefix="where `uId` in">
<if test="list.size>0">
<foreach item="temp" collection="list" open="(" close=")" separator=",">
#{temp}
</foreach>
</if>
</trim>
</select>
<!--使用List物件入參，Foreach遍歷-->
<select id="userListForeachs" resultType="User">
<include refid="cols"/>
<trim prefix="where `uId` in">
<if test="list.size>0">
<foreach item="temp" collection="list" open="(" close=")" separator=",">
#{temp.uId}
</foreach>
</if>
</trim>
</select>
<!--使用Map+List集合入參-->
<select id="userMapForeach" resultType="User">
<include refid="cols"/>
<where>
<if test="mapList.size>0">
`uId` in
<foreach collection="mapList" open="(" close=")" item="temp" separator=",">
#{temp}
</foreach>
</if>
</where>
</select>
<select id="userMap" resultType="User">
<include refid="cols"/>
<where>
`uId` in (#{one})
</where>
</select>
<!--使用註解入參Map-->
<select id="userMapTow" resultType="User">
<include refid="cols"/>
<where>
`uId` in
<if test="ars.keys.size>0">
<foreach collection="ars.keys" open="(" separator="," close=")" item="key" index="ind">
<!--通過鍵獲取value-->
#{ars[${key}].uId}
<!--直接獲取key-->
<!--#{key}-->
</foreach>
</if>
</where>
</select>
</mapper>
UserText：
package mlq;
import mlq.bean.User;
import mlq.Mapper.UserMappers;
import mlq.util.MyBatisTool;
import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class UserText {
//連線SQLSession
private SqlSession sqlSession = null;
private UserMappers mapper = null;
//測試前置增強
@Before
public void before() {
sqlSession = MyBatisTool.getSqlSession();
mapper = sqlSession.getMapper(UserMappers.class);
}
//測試後置增強
@After
public void after() {
sqlSession.commit();
sqlSession.close();
}
/**
* 查詢使用者資訊
*/
@Test
public void userAllList() {
User user = new User();
user.setUserName("MLQ");
user.setUId(20180001);
List<User> users = mapper.userAllList(user);
System.out.println(users);
}
@Test
public void userAllListTow() {
User user = new User();
user.setUserName("MLQ");
user.setUId(20180001);
List<User> users = mapper.userAllListTow(user);
System.out.println(users);
}
@Test
public void userAllListChoose() {
User user = new User();
user.setUserName("FKX");
user.setUId(20180002);
List<User> users = mapper.userAllListChoose(user);
System.out.println(users);
}
/**
* 更新使用者資訊
*/
@Test
public void updUser() {
User user = new User();
user.setRealName("MLQMLQ");
user.setUserPwd("456");
user.setUserName("MLQ");
user.setUId(20180001);
int i = mapper.updUser(user);
System.out.println((i > 0) ? "更新成功" : "更新失敗！！！");
}
@Test
public void updUserTow() {
User user = new User();
user.setRealName("MLQ");
user.setUserPwd("123");
user.setUserName("MLQ");
user.setUId(20180001);
int i = mapper.updUser(user);
System.out.println((i > 0) ? "更新成功" : "更新失敗！！！");
}
/**
* 使用陣列入參Foreach遍歷
*/
@Test
public void arrayList() {
int[] ars = {20180001, 20180002};
List<User> users = mapper.userArrays(ars);
System.err.println(users);
}
/**
* 使用List入參Foreach遍歷
*/
@Test
public void userListForeach() {
List<String> list = new ArrayList<String>();
list.add("20180001");
list.add("20180002");
List<User> users = mapper.userListForeach(list);
System.out.println(users);
}
@Test
public void userListForeachs() {
List<User> list = new ArrayList<User>();
User user = new User();
user.setUId(20180001);
User user1 = new User();
user1.setUId(20180002);
list.add(user);
list.add(user1);
List<User> users = mapper.userListForeachs(list);
System.err.println(users);
}
//使用Map集合入參Foreach遍歷
@Test
public void userMapForeach() {
Map<String, Object> map = new HashMap<String, Object>();
List<Integer> list = new ArrayList<Integer>();
list.add(20180001);
list.add(20180002);
map.put("one", 20180001);
map.put("mapList", list);
List<User> users = mapper.userMapForeach(map);
System.err.println(users);
}
//使用Map集合入參Foreach遍歷
@Test
public void userMap() {
Map<String, Object> map = new HashMap<String, Object>();
List<Integer> list = new ArrayList<Integer>();
list.add(20180001);
list.add(20180002);
map.put("one", 20180001);
map.put("mapList", list);
List<User> users = mapper.userMap(map);
System.err.println(users);
}
/**
* 入參Map集合使用註解標註資訊
*/
@Test
public void userMapTow() {
Map<String, User> map = new HashMap<String, User>();
User user = new User(20180001);
User user1 = new User(20180002);
map.put("20180001", user);
map.put("20180002", user1);
List<User> users = mapper.userMapTow(map);
System.err.println(users);
}
}