MongoDB Query เลือก 10 เอกสารล่าสุดโดยไม่เปลี่ยนลำดับ

การเลือก 10 เอกสารล่าสุดด้วย skip()

สำหรับการนี้ ให้ใช้ skip() ใน MongoDB ภายใต้ skip() ให้ตั้งค่า "count() - 10" เพื่อดึง 10 เอกสารล่าสุด

สร้าง Collection พร้อมข้อมูล

> db.demo500.insertOne({value:10});
{ "acknowledged" : true, "insertedId" : ObjectId("5e8749c5987b6e0e9d18f55a") }
> db.demo500.insertOne({value:1200});
{ "acknowledged" : true, "insertedId" : ObjectId("5e8749c8987b6e0e9d18f55b") }
> db.demo500.insertOne({value:19});
{ "acknowledged" : true, "insertedId" : ObjectId("5e8749cb987b6e0e9d18f55c") }
> db.demo500.insertOne({value:28});
{ "acknowledged" : true, "insertedId" : ObjectId("5e8749cf987b6e0e9d18f55d") }
> db.demo500.insertOne({value:50});
{ "acknowledged" : true, "insertedId" : ObjectId("5e8749d1987b6e0e9d18f55e") }
> db.demo500.insertOne({value:70});
{ "acknowledged" : true, "insertedId" : ObjectId("5e8749d4987b6e0e9d18f55f") }
> db.demo500.insertOne({value:100});
{ "acknowledged" : true, "insertedId" : ObjectId("5e8749d7987b6e0e9d18f560") }
> db.demo500.insertOne({value:10});
{ "acknowledged" : true, "insertedId" : ObjectId("5e8749d9987b6e0e9d18f561") }
> db.demo500.insertOne({value:98});
{ "acknowledged" : true, "insertedId" : ObjectId("5e8749dc987b6e0e9d18f562") }
> db.demo500.insertOne({value:80});
{ "acknowledged" : true, "insertedId" : ObjectId("5e8749e0987b6e0e9d18f563") }
> db.demo500.insertOne({value:75});
{ "acknowledged" : true, "insertedId" : ObjectId("5e874c73987b6e0e9d18f564") }
> db.demo500.insertOne({value:68});
{ "acknowledged" : true, "insertedId" : ObjectId("5e874c78987b6e0e9d18f565") }

แสดงเอกสารทั้งหมด

> db.demo500.find();

ผลลัพธ์:

{ "_id" : ObjectId("5e8749c5987b6e0e9d18f55a"), "value" : 10 }
{ "_id" : ObjectId("5e8749c8987b6e0e9d18f55b"), "value" : 1200 }
{ "_id" : ObjectId("5e8749cb987b6e0e9d18f55c"), "value" : 19 }
{ "_id" : ObjectId("5e8749cf987b6e0e9d18f55d"), "value" : 28 }
{ "_id" : ObjectId("5e8749d1987b6e0e9d18f55e"), "value" : 50 }
{ "_id" : ObjectId("5e8749d4987b6e0e9d18f55f"), "value" : 70 }
{ "_id" : ObjectId("5e8749d7987b6e0e9d18f560"), "value" : 100 }
{ "_id" : ObjectId("5e8749d9987b6e0e9d18f561"), "value" : 10 }
{ "_id" : ObjectId("5e8749dc987b6e0e9d18f562"), "value" : 98 }
{ "_id" : ObjectId("5e8749e0987b6e0e9d18f563"), "value" : 80 }
{ "_id" : ObjectId("5e874c73987b6e0e9d18f564"), "value" : 75 }
{ "_id" : ObjectId("5e874c78987b6e0e9d18f565"), "value" : 68 }

คิวรีเลือก 10 เอกสารล่าสุด

> db.demo500.find().skip(db.demo500.count() - 10);

ผลลัพธ์:

{ "_id" : ObjectId("5e8749cb987b6e0e9d18f55c"), "value" : 19 }
{ "_id" : ObjectId("5e8749cf987b6e0e9d18f55d"), "value" : 28 }
{ "_id" : ObjectId("5e8749d1987b6e0e9d18f55e"), "value" : 50 }
{ "_id" : ObjectId("5e8749d4987b6e0e9d18f55f"), "value" : 70 }
{ "_id" : ObjectId("5e8749d7987b6e0e9d18f560"), "value" : 100 }
{ "_id" : ObjectId("5e8749d9987b6e0e9d18f561"), "value" : 10 }
{ "_id" : ObjectId("5e8749dc987b6e0e9d18f562"), "value" : 98 }
{ "_id" : ObjectId("5e8749e0987b6e0e9d18f563"), "value" : 80 }
{ "_id" : ObjectId("5e874c73987b6e0e9d18f564"), "value" : 75 }
{ "_id" : ObjectId("5e874c78987b6e0e9d18f565"), "value" : 68 }