你可以用它来完成
db.test.update(
{ _id : 133 },
{ $set : { PackSizes: {_id: 123, PackSizeName:"xyz", UnitName:"pqr"}} }
)
PackSizes可以是任何带有数组或不带数组的文档。
您的结果文档将是:
{
"_id" : 133,
"Name" : "abc",
"Price" : 20,
"PackSizes" : {
"_id" : 123,
"PackSizeName" : "xyz",
"UnitName" : "pqr"
}
}
更新:
添加新字段和一个成员到数组中,
假设我们有您的原始文档。
{
_id: 133,
Name: "abc",
Price: 20
}
步骤1:添加新字段:PackSizes 是一个数组
db.test.update(
{ _id : 133 },
{ $set : {PackSizes: [ {_id: 123, PackSizeName:"xyz", UnitName:"pqr"}]}}
)
步骤2:将新项目推送到数组中
db.test.update(
{ _id : 133 },
{ $push : { PackSizes: {_id: 124, PackSizeName:"xyz", UnitName:"pqr"}} }
)
而且你将拥有
{
"_id" : 133,
"Name" : "abc",
"Price" : 20,
"PackSizes" : [
{
"_id" : 123,
"PackSizeName" : "xyz",
"UnitName" : "pqr"
},
{
"_id" : 124,
"PackSizeName" : "xyz",
"UnitName" : "pqr"
}
]
}