我有一个文件如下的集合(MongoDB):
{
_id: 'ABPS1001',
Brand: 'DecNag',
serial: '2393-829-109',
resume: [
{
status: '1',
nameAg: 'Gina',
lastNameAg: 'Saenz',
coord_id: '1025',
movDate: '25-10-2016 11:33'
},
{
status: '0',
techID: '11',
coord_id: '1025',
movDate: '30-10-2016 16:29',
idReplace: 'ABPS1026'
},
{
status: '1',
nameAg: 'Diana',
lastNameAg: 'Gutierrez',
coord_id: '1014',
techID: '10',
movDate: '04-11-2016 09:12'
},
{
status: '0',
techID: '12',
coord_id: '1014',
movDate: '30-11-2016 16:25',
idReplace: 'ABPS1021'
},
{
status: '1',
nameAg: 'Laura',
lastNameAg: 'Diaz',
coord_id: '1012',
techID: '11',
movDate: '04-12-2016 11:33'
},
{
status: '0',
techID: '10',
coord_id: '1012',
movDate: '22-12-2016 12:21',
idReplace: 'ABPS1107'
},
{
status: '1',
nameAg: '172.27.48.125',
lastNameAg: '',
coord_id: '1004',
techID: '12',
movDate: '27-12-2016 08:30'
},
{
status: '0',
techID: '11',
movDate: '02-02-2017 14:12',
idReplace: 'ABPS1107'
}
]
}
我需要从文档“resume”获取最后一个条目,其中_id:'ABPS1001'代替整个文档。有没有办法使用MongoDB语句而不是使用编程语言进行处理?
另外,如何在“resume”上为任何一组值添加或删除值(例如,如果我想在“resume”的最后一组中添加“coord_id”)?
谢谢!
答案 0 :(得分:1)
以下是如何使用聚合来完成问题的第一部分:
// Returns last value of the resume array...
// First - Match the document
// Second - Project to slice the last element of the resume array and put it into a new document called lastValue
db.foo.aggregate([
{ $match: {"_id": "ABPS1001"} },
{ $project: { lastValue: { $slice: [ "$resume", -1 ] } } }
])
结果:
{
"_id" : "ABPS1001",
"lastValue" : [
{
"status" : "0",
"techID" : "11",
"movDate" : "02-02-2017 14:12",
"idReplace" : "ABPS1107"
}
]
}
对于第二部分,您可以使用' $'进行位置更新。运算符see here