Tk.mybatis零sql语句实现动态sql查询的方法(4种)

<select id="findStudentByCondition" resultType="com.example.service.entity.Student">
    SELECT id, name, score FROM tbl_student
    <where>
      <if test="score !=null and score > 0">
        score > #{score}
      </if>
      <if test="name !=null and name != ''">
         <bind name="pattern" value=" '%' + name + '%' "/>
        AND name LIKE #{pattern}
      </if>
    </where>
    ORDER BY score DESc
  </select>

/**
   * 第一种：使用example查询
   */
  @Test
  public void testSelectByExample() {
    Example example = new Example(Student.class);
    // 设置查询列
    example.selectProperties("id","name","score");
    // 动态sql
    example.and()
        .andGreaterThan("score",90)
        .andLike("name", "%i%");
    // 去重
    example.setDistinct(true);
    // 排序
    example.orderBy("score").desc();
    List<Student> students = studentMapper.selectByExample(example);
    System.out.println(students);
  }

/**
   * 第二种：使用example.createCriteria查询
   */
  @Test
  public void testSelectByExampleCriteria() {
    Example example = new Example(Student.class);
    // 设置查询列
    example.selectProperties("id","name","score");
    // 动态查询
    example.createCriteria()
        .andGreaterThan("score",90)
        .andLike("name", "%i%");
    // 去重
    example.setDistinct(true);
    // 排序
    example.orderBy("score").desc();
    List<Student> students = studentMapper.selectByExample(example);
    System.out.println(students);
  }

/**
   * 第三种：使用Example.builder实现
   */
  @Test
  public void testSelectByExampleBuilder() {
    Example example = Example.builder(Student.class)
        // 查询列
        .select("id","name","score")
        // 动态sql
        .where(Sqls.custom()
            .andGreaterThan("score",90)
            .andLike("name","%i%"))
        // 去重
        .distinct()
        // 排序
        .orderByDesc("score")
        .build();
    List<Student> students = studentMapper.selectByExample(example);
    System.out.println(students);
  }

/**
   * 第四种：使用weekendSqls实现
   */
  @Test
  public void testSelectByWeekendSqls() {
    WeekendSqls<Student> sqls = WeekendSqls.custom();
    sqls = sqls
        .andGreaterThan(Student::getScore,90)
        .andLike(Student::getName,"%i%");
    List<Student> sysRoles = studentMapper.selectByExample(Example.builder(Student.class)
        .select("id","name","score")
        .where(sqls)
        .distinct()
        .orderByDesc("score")
        .build());
    System.out.println(sysRoles);
 
  }