user [{
         id: 1,
         name: "jack",
         age: "22",
         city_id: 1,
         job_id: 1
     },
     {
         id: 2,
         name: "yoyo",
         age: "22",
         city_id: 2,
         job_id: 2
     }];

     city [{
         id: 1,
         name: "beijin"
     },
     {  
        id: 2,
        name: "shanghai"
     }]

单独查询表的结果是这样的，我想实现类似下面的扩展结果要怎么操作，看了api文档还是不太明白

user [{
         id: 1,
         name: "jack",
         age: "22",
         city: {id: 1, name: "beijin"},
         job_id: {id:1, name: "dev"}
     },
     {
         id: 2,
         name: "yoyo",
         age: "22",
         city: {id: 2, name: "shanghai"},
         job: {id: 2, name: "art"}
     }];