mongoose – 如何sorting多种标准的人口
我正在尝试对group.name首先填充“group.name”的angular色文档进行sorting，然后再对role.name进行sorting
return this.find(query, { _group: 1, name: 1, _id:0 } ) .populate('_group', 'name -_id') .sort({ '_group.name': 1, name: 1 }) 但它不能按预期工作，我只能在role.name上sorting
ROLES:[ {"name":"NewRole"}, {"name":"NewRoleInGroup","_group":{"name":"GroupA"}}, {"_group":{"name":"GroupA"},"name":"admin"}, {"_group":{"name":"GroupA"},"name":"employee"}, {"_group":{"name":"GroupB"},"name":"employee"}, {"_group":{"name":"GroupC"},"name":"employee"}, {"_group":{"name":"GroupA"},"name":"manager"}, {"_group":{"name":"GroupB"},"name":"manager"}, {"name":"visitor"} ]
我想得到的是：
ROLES:[ // NO GROUP {"name":"NewRole"}, {"name":"visitor"}. // GroupA {"_group":{"name":"GroupA"},"name":"admin"}, {"_group":{"name":"GroupA"},"name":"employee"}, {"_group":{"name":"GroupA"},"name":"manager"}, {"name":"NewRoleInGroup","_group":{"name":"GroupA"}}, // GroupB {"_group":{"name":"GroupB"},"name":"employee"}, {"_group":{"name":"GroupB"},"name":"manager"}, // GroupC {"_group":{"name":"GroupC"},"name":"employee"} ]
感谢您的反馈
更新根据@Talha评论：
使用聚合，我接近我所需要的…但是，我得到一个数组内的数据，在多对一的关系只有一个组在这种情况下…如何投影组作为数组中的第一个对象：“group”：{}或“group”：{“name”; …，“description”：…}？
return this.aggregate([ { $match: query}, { $lookup: { from: 'groups', localField: '_group', foreignField: '_id', as: 'group' } } , { $project: { 'group.name': 1, 'group.description': 1, name: 1, description: 1, _id: 0 } }, { $sort: { 'name': 1 } }, { $limit: limit }, { $skip: skip } ]) ROLES: [ // NO GROUP {"name":"NewRole","description":"NewRole description","group":[]}, {"name":"Visitor","description":"no permissions","group":[]}, // GROUP A {"name":"NewRoleInGroup","description":"NewRoleInGroup description","group":[{"name":"GroupA","description":"Description GroupA"}]}, {"name":"admin","description":"can RW group, user","group":[{"name":"GroupA","description":"Description GroupA"}]}, {"name":"employee","description":"can R group, can read user","group":[{"name":"GroupA","description":"Description GroupA"}]}, {"name":"manager","description":"can R group, can RW user","group":[{"name":"GroupA","description":"Description GroupA"}]}, // GROUP B {"name":"employee","description":"can R group, can read user","group":[{"name":"GroupB","description":"Description GroupB"}]}, {"name":"manager","description":"can R group, can RW user","group":[{"name":"GroupB","description":"Description GroupB"}]}, // GROUP C {"name":"employee","description":"can R group, can read user","group":[{"name":"GroupC","description":"Description GroupC"}]}]
我应该使用下面的函数w聚合：
return this.aggregate([ { $match: query}, { $lookup: { from: 'groups', localField: '_group', foreignField: '_id', as: 'group' } }, { $project: { group: { $let:{ vars:{ firstGroup:{ $arrayElemAt:["$group",0] } }, in:{ name:"$$firstGroup.name", description:"$$firstGroup.description" } } }, name: 1, description: 1, _id: 0 } }, { $sort: { 'group.name': 1, 'name': 1 } }, { $limit: limit }, { $skip: skip } ]) .exec() .then((list) => { return list; })
这将输出正确sorting的列表（1 / group.name 2 / ny role.name）与查找输出数组之外的组：
ROLES: [ // NO GROUP {"name":"NewRole","description":"NewRole description","group":{}}, {"name":"Visitor","description":"no permissions","group":{}}, // GROUP A {"name":"NewRoleInGroup","description":"NewRoleInGroup description","group":{"name":"GroupA","description":"Description GroupA"}}, {"name":"admin","description":"can RW group, user","group":{"name":"GroupA","description":"Description GroupA"}}, {"name":"employee","description":"can R group, can read user","group":{"name":"GroupA","description":"Description GroupA"}}, {"name":"manager","description":"can R group, can RW user","group":{"name":"GroupA","description":"Description GroupA"}}, // GROUP B {"name":"employee","description":"can R group, can read user","group":{"name":"GroupB","description":"Description GroupB"}}, {"name":"manager","description":"can R group, can RW user","group":{"name":"GroupB","description":"Description GroupB"}}, // GROUP C {"name":"employee","description":"can R group, can read user","group":{"name":"GroupC","description":"Description GroupC"}}]