想要文档中存在的子文档,来自 MongoDB 数据库
Want a sub document which is present in document, from MongoDB Database
我有一个 Json 数据存储在我的 MongoDB 数据库中,如下所示,
{
"_id" : ObjectId("5f17109a9013adc57942af2a"),
"name" : "Demo Name",
"dob" : "04/01/2000",
"phone" : "1234567890",
"email" : "demoname@gmail.com",
"password" : "0987",
"cPass" : "0987",
"location" : "Civil line, Mumbai"
}
我只想要一个名称(子文档),即整个文档中的演示名称:
: Demo Name
我正在写这个查询:
var employ = await coll.findOne( { "email": "demoname@gmail.com" } );
但它在 var employ 中为我提供了整个文档。我只想在 var employ 中使用名称。我怎样才能用 Mongo Dart 做到这一点。
此查询查找 email 值与“demoname@gmail.com”匹配的元素,找到元素后,它将排除字段,即 _id、dob、phone、email、密码、cPass 和位置。该值仍然是“Demo Name”及其键。
var employ = await coll
.find(where.match("email", "demoname@gmail.com").excludeFields([
"_id",
"dob",
"phone",
"email",
"password",
"cPass",
"location",
]))
.toList();
要删除密钥,我们必须使用以下代码。
var arrayEle = employ[0]; // This statement can store the value in arrayEle from zeroth position.
var empName = arrayEle['name']; // This statement can remove the key "name" and only value of the key i.e "Demo Name" gets stored in empName variable.
print(empName); // This statment print the value stored in empName which is "Demo Name".
我有一个 Json 数据存储在我的 MongoDB 数据库中,如下所示,
{
"_id" : ObjectId("5f17109a9013adc57942af2a"),
"name" : "Demo Name",
"dob" : "04/01/2000",
"phone" : "1234567890",
"email" : "demoname@gmail.com",
"password" : "0987",
"cPass" : "0987",
"location" : "Civil line, Mumbai"
}
我只想要一个名称(子文档),即整个文档中的演示名称:
: Demo Name
我正在写这个查询:
var employ = await coll.findOne( { "email": "demoname@gmail.com" } );
但它在 var employ 中为我提供了整个文档。我只想在 var employ 中使用名称。我怎样才能用 Mongo Dart 做到这一点。
此查询查找 email 值与“demoname@gmail.com”匹配的元素,找到元素后,它将排除字段,即 _id、dob、phone、email、密码、cPass 和位置。该值仍然是“Demo Name”及其键。
var employ = await coll
.find(where.match("email", "demoname@gmail.com").excludeFields([
"_id",
"dob",
"phone",
"email",
"password",
"cPass",
"location",
]))
.toList();
要删除密钥,我们必须使用以下代码。
var arrayEle = employ[0]; // This statement can store the value in arrayEle from zeroth position.
var empName = arrayEle['name']; // This statement can remove the key "name" and only value of the key i.e "Demo Name" gets stored in empName variable.
print(empName); // This statment print the value stored in empName which is "Demo Name".