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07_动态SQL与模糊查询

时间:2015-09-15 16:13:01      阅读:251      评论:0      收藏:0      [点我收藏+]

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1 需求

    实现多条件查询用户
  • 姓名模糊匹配
  • 年龄在指定的最小值到最大值之间

2 准备表和数据

  1. create table d_user(
  2. id int primary key auto_increment,
  3. name varchar(10),
  4. age int(3)
  5. );
  6. insert into d_user(name,age) values(‘Tom‘,12);
  7. insert into d_user(name,age) values(‘Bob‘,13);
  8. insert into d_user(name,age) values(‘Jack‘,18);

3 ConditionUser(查询条件实例类)

  1. private String name;
  2. private int minAge;
  3. private int maxAge;

4 userMapper.xml(映射文件)

  1. <mapper namespace="cn.imentors.mybatis.test7.userMapper">
  2. <!--
  3. 实现多条件查询用户(姓名模糊匹配, 年龄在指定的最小值到最大值之间)
  4. -->
  5. <select id="getUser" parameterType="ConditionUser" resultType="User">
  6. select * from d_user where
  7. <if test=‘name != "%null%"‘>
  8. name like #{name} and
  9. </if>
  10. age between #{minAge} and #{maxAge}
  11. </select>
  12. </mapper>

5 测试

  1. @Test
  2. public void test(){
  3. SqlSessionFactory factory = MybatisUtils.getFactory();
  4. SqlSession session = factory.openSession();
  5. String statement = "cn.imentors.mybatis.test7.userMapper.getUser";
  6. String name = "o";
  7. name = null;
  8. ConditionUser parameter = new ConditionUser("%"+name+"%", 13, 18);
  9. List<User> list = session.selectList(statement, parameter);
  10. System.out.println(list);
  11. session.close();

6 MyBatis中可用的动态SQL标签

6.1 if

6.2 choose

  1. <select id=”findActiveBlogLike”parameterType=”Blog” resultType=”Blog”>
  2. SELECT * FROM BLOG WHERE state = ?ACTIVE?
  3. <choose>
  4. <when test=”title != null”>
  5. AND title like #{title}
  6. </when>
  7. <when test=”author != null and author.name != null”>
  8. AND title like #{author.name}
  9. </when>
  10. <otherwise>
  11. AND featured = 1
  12. </otherwise>
  13. </choose>
  14. </select>

6.3 where

  1. <select id=”findActiveBlogLike” parameterType=”Blog” resultType=”Blog”>
  2. SELECT * FROM BLOG
  3. <where>
  4. <if test=”state != null”>
  5. state = #{state}
  6. </if>
  7. <if test=”title != null”>
  8. AND title like #{title}
  9. </if>
  10. <if test=”author != null and author.name != null”>
  11. AND title like #{author.name}
  12. </if>
  13. </where>
  14. </select>

6.4 set

  1. <update id="updateAuthorIfNecessary"
  2. parameterType="domain.blog.Author">
  3. update Author
  4. <set>
  5. <if test="username != null">username=#{username},</if>
  6. <if test="password != null">password=#{password},</if>
  7. <if test="email != null">email=#{email},</if>
  8. <if test="bio != null">bio=#{bio}</if>
  9. </set>
  10. where id=#{id}
  11. </update>

6.5 foreach

  1. <select id="selectPostIn" resultType="domain.blog.Post">
  2. SELECT *
  3. FROM POST P
  4. WHERE ID in
  5. <foreach item="item" index="index" collection="list" open="(" separator="," close=")">
  6. #{item}
  7. </foreach>
  8. </select>
注:你可以传递一个List实例或者数组作为参数对象传给MyBatis。当你这么做的时候,MyBatis会自动将它包装在一个Map中,用名称作为键。List实例将会以“list”作为键,而数组实例将会以“array”作为键


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07_动态SQL与模糊查询

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原文地址:http://www.cnblogs.com/mentorStudio/p/4810470.html

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