I have this monogdb schema:
groups = {
"bsonType": "object",
"required": [
"created_at", "group_name", "owner",
"members", "currency", "country",
"group_username"
],
"properties": {
"created_at": {
"bsonType": "date",
"description": "The date and time when the group was created"
},
"group_name": {
"bsonType": "string",
"description": "Name of group"
},
"group_username": {
"bsonType": "string",
"description": "groups username"
},
"country": {
"bsonType": "string",
"description": "User's country and is required"
},
"currency": {
"bsonType": "string",
"description": "User's currency type and is required"
},
"description": {
"bsonType": "string",
"description": "Brief description of what the group does"
},
"block": {
"bsonType": "bool",
"description": "Field to check if user disabled from group activity"
},
"owner": {
"bsonType": "object",
"required": ["user_id", "status"],
"properties": {
"user_id": {
"bsonType": "objectId",
"description": "User id of the owner of the group"
},
"status": {
"bsonType": "string",
"description": "Default value is 'owner'",
}
},
},
"group_invite_link": {
"bsonType": "string",
"description": "Link used to invite new members"
},
"members": {
"bsonType": "array",
"items": {
"bsonType": "object",
"required": ["user_id", "name", "status", "confirmed", "joined_at"],
"properties": {
"user_id": {
"bsonType": "objectId"
},
"name": {
"bsonType": "string",
"description": "Name of group member"
},
"status": {
"enum": ["admin", "member"],
"description": "can only be one of the enum values and is required"
},
"confirmed": {
"bsonType": "bool",
"description": "Confirms if user is fully authorized to operate in group"
},
"joined_at": {
"bsonType": "date",
"description": "Date user joined group"
}
}
}
},
"group_wallet_id": {
"bsonType": "objectId",
"description": "Id of wallet associated with group"
}
}
}
and I am querying it to return only documents that match the below query:
db.groups.find({
"$and": [
{
"members.user_id": ObjectId(user_id)
},
{
"members.confirmed": True
}
]
})
It returns this:
{
"sucess": true,
"message": "Users groups",
"data": [
{
"_id": "63987c4263d7eba1e79a1df1",
"created_at": "2022-12-13 13:21:03",
"group_name": "Demo 1",
"is_owner": true,
"balance": {
"$numberDecimal": "250.00"
},
"members": [
{
"user_id": "63987b7c63d7eba1e79a1dd7",
"name": "Joy Kudosen",
"status": "admin",
"confirmed": true,
"joined_at": "2022-12-13 13:21:03"
},
{
"user_id": "63987b7c63d7eba1e79a1dd8",
"name": "Joy Kudosen",
"status": "member",
"confirmed": true,
"joined_at": "2022-12-14 13:22:03"
},
{
"user_id": "63987b7c63d7eba1e79a1dd7",
"name": "Joy Kudosen",
"status": "admin",
"confirmed": true,
"joined_at": "2022-12-14 11:05:39"
}
]
},
{
"_id": "63987c5a63d7eba1e79a1df4",
"created_at": "2022-12-13 13:21:27",
"group_name": "Demo 2",
"is_owner": true,
"balance": {
"$numberDecimal": "100"
},
"members": [
{
"user_id": "63987b7c63d7eba1e79a1dd7",
"name": "Joy Kudosen",
"status": "admin",
"confirmed": true,
"joined_at": "2022-12-13 13:21:27"
}
]
},
{
"_id": "6399ae06ebaca8cd5fbcd639",
"created_at": "2022-12-14 11:05:39",
"group_name": "Demo 4",
"is_owner": true,
"balance": {
"$numberDecimal": "0"
},
"members": [
{
"user_id": "63987b7c63d7eba1e79a1dd7",
"name": "Joy Kudosen",
"status": "admin",
"confirmed": true,
"joined_at": "2022-12-14 11:05:39"
}
]
},
{
"_id": "63d1810699edcb7379f21c27",
"created_at": "2023-01-25 19:20:33",
"group_name": "Hello world",
"is_owner": false,
"balance": {
"$numberDecimal": "0"
},
"members": [
{
"user_id": "63d180c399edcb7379f21c23",
"name": "Joy Kudosen",
"status": "admin",
"confirmed": true,
"joined_at": "2023-01-25 19:20:33"
},
{
"user_id": "63987b7c63d7eba1e79a1dd7",
"name": "Joy Kudosen",
"status": "member",
"confirmed": false,
"joined_at": "2023-01-25 19:23:31"
}
]
}
]
}
I want to return only array objects that match the user’s id and "confirmed" value of "true" in the members array like this:
{
"sucess": true,
"message": "Users groups",
"data": [
{
"_id": "63987c4263d7eba1e79a1df1",
"created_at": "2022-12-13 13:21:03",
"group_name": "Demo 1",
"is_owner": true,
"balance": {
"$numberDecimal": "250.00"
},
"members": [
{
"user_id": "63987b7c63d7eba1e79a1dd7",
"name": "Joy Kudosen",
"status": "admin",
"confirmed": true,
"joined_at": "2022-12-13 13:21:03"
},
{
"user_id": "63987b7c63d7eba1e79a1dd8",
"name": "Joy Kudosen",
"status": "member",
"confirmed": true,
"joined_at": "2022-12-14 13:22:03"
},
{
"user_id": "63987b7c63d7eba1e79a1dd7",
"name": "Joy Kudosen",
"status": "admin",
"confirmed": true,
"joined_at": "2022-12-14 11:05:39"
}
]
},
{
"_id": "63987c5a63d7eba1e79a1df4",
"created_at": "2022-12-13 13:21:27",
"group_name": "Demo 2",
"is_owner": true,
"balance": {
"$numberDecimal": "100"
},
"members": [
{
"user_id": "63987b7c63d7eba1e79a1dd7",
"name": "Joy Kudosen",
"status": "admin",
"confirmed": true,
"joined_at": "2022-12-13 13:21:27"
}
]
},
{
"_id": "6399ae06ebaca8cd5fbcd639",
"created_at": "2022-12-14 11:05:39",
"group_name": "Demo 4",
"is_owner": true,
"balance": {
"$numberDecimal": "0"
},
"members": [
{
"user_id": "63987b7c63d7eba1e79a1dd7",
"name": "Joy Kudosen",
"status": "admin",
"confirmed": true,
"joined_at": "2022-12-14 11:05:39"
}
]
}
]
}
I have used different forms of this query but I am unable to filter out the "hello world" group information. I have tried aggregation and the "or" operation and still get the same results.
>Solution :
"$elemMatch" is used to find documents that match multiple fields within an array element.
For example, like this:
db.groups.find({
"members": {
"$elemMatch": {
"user_id": "63987b7c63d7eba1e79a1dd7",
"confirmed": true
}
}
})
Try it on mongoplayground.net.