9.3.5 使用生成的代码
需要将生成工程中所生成的代码拷贝到自己的工程中。
拷这4个到我们原来的spring_mybatis1216工程下
ItemsMapper.java
package cn.itcast.ssm.mapper; import cn.itcast.ssm.po.Items; import cn.itcast.ssm.po.ItemsExample; import java.util.List; import org.apache.ibatis.annotations.Param; public interface ItemsMapper { int countByExample(ItemsExample example); //删除符合条件的记录 int deleteByExample(ItemsExample example); //根据主键删除 int deleteByPrimaryKey(Integer id); //插入对象所有字段 int insert(Items record); //插入对象不为空的字段 int insertSelective(Items record); List<Items> selectByExampleWithBLOBs(ItemsExample example); //自定义查询条件查询结果集 List<Items> selectByExample(ItemsExample example); //根据主键查询 Items selectByPrimaryKey(Integer id); int updateByExampleSelective(@Param("record") Items record, @Param("example") ItemsExample example); int updateByExampleWithBLOBs(@Param("record") Items record, @Param("example") ItemsExample example); int updateByExample(@Param("record") Items record, @Param("example") ItemsExample example); //根据主键将对象中不为空的值更新至数据库 int updateByPrimaryKeySelective(Items record); int updateByPrimaryKeyWithBLOBs(Items record); //根据主键将对象中所有字段的值更新至数据库 int updateByPrimaryKey(Items record); }
ItemsMapper.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="cn.itcast.ssm.mapper.ItemsMapper" > <resultMap id="BaseResultMap" type="cn.itcast.ssm.po.Items" > <id column="id" property="id" jdbcType="INTEGER" /> <result column="name" property="name" jdbcType="VARCHAR" /> <result column="price" property="price" jdbcType="REAL" /> <result column="pic" property="pic" jdbcType="VARCHAR" /> <result column="createtime" property="createtime" jdbcType="TIMESTAMP" /> </resultMap> <resultMap id="ResultMapWithBLOBs" type="cn.itcast.ssm.po.Items" extends="BaseResultMap" > <result column="detail" property="detail" jdbcType="LONGVARCHAR" /> </resultMap> <sql id="Example_Where_Clause" > <where > <foreach collection="oredCriteria" item="criteria" separator="or" > <if test="criteria.valid" > <trim prefix="(" suffix=")" prefixOverrides="and" > <foreach collection="criteria.criteria" item="criterion" > <choose > <when test="criterion.noValue" > and ${criterion.condition} </when> <when test="criterion.singleValue" > and ${criterion.condition} #{criterion.value} </when> <when test="criterion.betweenValue" > and ${criterion.condition} #{criterion.value} and #{criterion.secondValue} </when> <when test="criterion.listValue" > and ${criterion.condition} <foreach collection="criterion.value" item="listItem" open="(" close=")" separator="," > #{listItem} </foreach> </when> </choose> </foreach> </trim> </if> </foreach> </where> </sql> <sql id="Update_By_Example_Where_Clause" > <where > <foreach collection="example.oredCriteria" item="criteria" separator="or" > <if test="criteria.valid" > <trim prefix="(" suffix=")" prefixOverrides="and" > <foreach collection="criteria.criteria" item="criterion" > <choose > <when test="criterion.noValue" > and ${criterion.condition} </when> <when test="criterion.singleValue" > and ${criterion.condition} #{criterion.value} </when> <when test="criterion.betweenValue" > and ${criterion.condition} #{criterion.value} and #{criterion.secondValue} </when> <when test="criterion.listValue" > and ${criterion.condition} <foreach collection="criterion.value" item="listItem" open="(" close=")" separator="," > #{listItem} </foreach> </when> </choose> </foreach> </trim> </if> </foreach> </where> </sql> <sql id="Base_Column_List" > id, name, price, pic, createtime </sql> <sql id="Blob_Column_List" > detail </sql> <select id="selectByExampleWithBLOBs" resultMap="ResultMapWithBLOBs" parameterType="cn.itcast.ssm.po.ItemsExample" > select <if test="distinct" > distinct </if> <include refid="Base_Column_List" /> , <include refid="Blob_Column_List" /> from items <if test="_parameter != null" > <include refid="Example_Where_Clause" /> </if> <if test="orderByClause != null" > order by ${orderByClause} </if> </select> <select id="selectByExample" resultMap="BaseResultMap" parameterType="cn.itcast.ssm.po.ItemsExample" > select <if test="distinct" > distinct </if> <include refid="Base_Column_List" /> from items <if test="_parameter != null" > <include refid="Example_Where_Clause" /> </if> <if test="orderByClause != null" > order by ${orderByClause} </if> </select> <select id="selectByPrimaryKey" resultMap="ResultMapWithBLOBs" parameterType="java.lang.Integer" > select <include refid="Base_Column_List" /> , <include refid="Blob_Column_List" /> from items where id = #{id,jdbcType=INTEGER} </select> <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" > delete from items where id = #{id,jdbcType=INTEGER} </delete> <delete id="deleteByExample" parameterType="cn.itcast.ssm.po.ItemsExample" > delete from items <if test="_parameter != null" > <include refid="Example_Where_Clause" /> </if> </delete> <insert id="insert" parameterType="cn.itcast.ssm.po.Items" > insert into items (id, name, price, pic, createtime, detail ) values (#{id,jdbcType=INTEGER}, #{name,jdbcType=VARCHAR}, #{price,jdbcType=REAL}, #{pic,jdbcType=VARCHAR}, #{createtime,jdbcType=TIMESTAMP}, #{detail,jdbcType=LONGVARCHAR} ) </insert> <insert id="insertSelective" parameterType="cn.itcast.ssm.po.Items" > insert into items <trim prefix="(" suffix=")" suffixOverrides="," > <if test="id != null" > id, </if> <if test="name != null" > name, </if> <if test="price != null" > price, </if> <if test="pic != null" > pic, </if> <if test="createtime != null" > createtime, </if> <if test="detail != null" > detail, </if> </trim> <trim prefix="values (" suffix=")" suffixOverrides="," > <if test="id != null" > #{id,jdbcType=INTEGER}, </if> <if test="name != null" > #{name,jdbcType=VARCHAR}, </if> <if test="price != null" > #{price,jdbcType=REAL}, </if> <if test="pic != null" > #{pic,jdbcType=VARCHAR}, </if> <if test="createtime != null" > #{createtime,jdbcType=TIMESTAMP}, </if> <if test="detail != null" > #{detail,jdbcType=LONGVARCHAR}, </if> </trim> </insert> <select id="countByExample" parameterType="cn.itcast.ssm.po.ItemsExample" resultType="java.lang.Integer" > select count(*) from items <if test="_parameter != null" > <include refid="Example_Where_Clause" /> </if> </select> <update id="updateByExampleSelective" parameterType="map" > update items <set > <if test="record.id != null" > id = #{record.id,jdbcType=INTEGER}, </if> <if test="record.name != null" > name = #{record.name,jdbcType=VARCHAR}, </if> <if test="record.price != null" > price = #{record.price,jdbcType=REAL}, </if> <if test="record.pic != null" > pic = #{record.pic,jdbcType=VARCHAR}, </if> <if test="record.createtime != null" > createtime = #{record.createtime,jdbcType=TIMESTAMP}, </if> <if test="record.detail != null" > detail = #{record.detail,jdbcType=LONGVARCHAR}, </if> </set> <if test="_parameter != null" > <include refid="Update_By_Example_Where_Clause" /> </if> </update> <update id="updateByExampleWithBLOBs" parameterType="map" > update items set id = #{record.id,jdbcType=INTEGER}, name = #{record.name,jdbcType=VARCHAR}, price = #{record.price,jdbcType=REAL}, pic = #{record.pic,jdbcType=VARCHAR}, createtime = #{record.createtime,jdbcType=TIMESTAMP}, detail = #{record.detail,jdbcType=LONGVARCHAR} <if test="_parameter != null" > <include refid="Update_By_Example_Where_Clause" /> </if> </update> <update id="updateByExample" parameterType="map" > update items set id = #{record.id,jdbcType=INTEGER}, name = #{record.name,jdbcType=VARCHAR}, price = #{record.price,jdbcType=REAL}, pic = #{record.pic,jdbcType=VARCHAR}, createtime = #{record.createtime,jdbcType=TIMESTAMP} <if test="_parameter != null" > <include refid="Update_By_Example_Where_Clause" /> </if> </update> <update id="updateByPrimaryKeySelective" parameterType="cn.itcast.ssm.po.Items" > update items <set > <if test="name != null" > name = #{name,jdbcType=VARCHAR}, </if> <if test="price != null" > price = #{price,jdbcType=REAL}, </if> <if test="pic != null" > pic = #{pic,jdbcType=VARCHAR}, </if> <if test="createtime != null" > createtime = #{createtime,jdbcType=TIMESTAMP}, </if> <if test="detail != null" > detail = #{detail,jdbcType=LONGVARCHAR}, </if> </set> where id = #{id,jdbcType=INTEGER} </update> <update id="updateByPrimaryKeyWithBLOBs" parameterType="cn.itcast.ssm.po.Items" > update items set name = #{name,jdbcType=VARCHAR}, price = #{price,jdbcType=REAL}, pic = #{pic,jdbcType=VARCHAR}, createtime = #{createtime,jdbcType=TIMESTAMP}, detail = #{detail,jdbcType=LONGVARCHAR} where id = #{id,jdbcType=INTEGER} </update> <update id="updateByPrimaryKey" parameterType="cn.itcast.ssm.po.Items" > update items set name = #{name,jdbcType=VARCHAR}, price = #{price,jdbcType=REAL}, pic = #{pic,jdbcType=VARCHAR}, createtime = #{createtime,jdbcType=TIMESTAMP} where id = #{id,jdbcType=INTEGER} </update> </mapper>
测试ItemsMapper中的方法
ItemsMapperTest.java
package cn.itcast.ssm.mapper; import java.util.Date; import java.util.List; import org.junit.Before; import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import cn.itcast.ssm.po.Items; import cn.itcast.ssm.po.ItemsExample; public class ItemsMapperTest { private ApplicationContext applicationContext; private ItemsMapper itemsMapper; //在setUp()这个方法得到spring容器 @Before public void setUp() throws Exception { applicationContext = new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml"); itemsMapper = (ItemsMapper) applicationContext.getBean("itemsMapper"); } //自定义条件查询 @Test public void testSelectByExample() { ItemsExample itemsExample = new ItemsExample(); //通过criteria构造查询条件 ItemsExample.Criteria criteria = itemsExample.createCriteria(); criteria.andNameEqualTo("笔记本"); //可能返回多条记录 List<Items> list = itemsMapper.selectByExample(itemsExample); System.out.println(list); } //根据主键查询 @Test public void testSelectByPrimaryKey() { Items items = itemsMapper.selectByPrimaryKey(1); System.out.println(items); } //插入 @Test public void testInsert() { //构造items对象 Items items = new Items(); items.setName("手机"); items.setPrice(900f); items.setDetail("不错"); items.setCreatetime(new Date()); itemsMapper.insert(items); } //根据主键删除 @Test public void testDeleteByPrimaryKey() { itemsMapper.deleteByPrimaryKey(4); } //更新数据 @Test public void testUpdateByPrimaryKey() { //对所有字段进行更新，需要先查询出来再更新 Items items = itemsMapper.selectByPrimaryKey(1); items.setName("水杯"); itemsMapper.updateByPrimaryKey(items); //如果传入字段不空为才更新，在批量更新中使用此方法，不需要先查询再更新 //itemsMapper.updateByPrimaryKeySelective(record); } }
9.4 逆向工程注意事项
9.4.1 Mapper文件内容不覆盖而是追加
XXXMapper.xml文件已经存在时，如果进行重新生成则mapper.xml文件内容不被覆盖而是进行内容追加，结果导致mybatis解析失败。
解决方法：删除原来已经生成的mapper xml文件再进行生成。
Mybatis自动生成的po及mapper.java文件不是内容而是直接覆盖没有此问题。
9.4.2 Table schema问题
下边是关于针对oracle数据库表生成代码的schema问题：
Schma即数据库模式，oracle中一个用户对应一个schema，可以理解为用户就是schema。
当Oralce数据库存在多个schema可以访问相同的表名时，使用mybatis生成该表的mapper.xml将会出现mapper.xml内容重复的问题，结果导致mybatis解析错误。
解决方法：在table中填写schema，如下：
<table schema="XXXX" tableName=" " >
XXXX即为一个schema的名称，生成后将mapper.xml的schema前缀批量去掉，如果不去掉当oracle用户变更了sql语句将查询失败。
快捷操作方式：mapper.xml文件中批量替换：“from XXXX.”为空
Oracle查询对象的schema可从dba_objects中查询，如下：
select * from dba_objects