如何用 MongoDB 實現分頁?
藉助 MongoDB 中的 limit() 和 skip(),可以實現分頁。
讓我們建立一個文件集合來理解這個概念。建立一個文件集合的查詢如下所示 −
> db.paginationDemo.insertOne({"CustomerName":"Chris","CustomerAge":23});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c949de44cf1f7a64fa4df52")
}
> db.paginationDemo.insertOne({"CustomerName":"Robert","CustomerAge":26});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c949df14cf1f7a64fa4df53")
}
> db.paginationDemo.insertOne({"CustomerName":"David","CustomerAge":24});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c949dfc4cf1f7a64fa4df54")
}
> db.paginationDemo.insertOne({"CustomerName":"Carol","CustomerAge":28});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c949e3e4cf1f7a64fa4df55")
}
> db.paginationDemo.insertOne({"CustomerName":"Bob","CustomerAge":29});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c949e474cf1f7a64fa4df56")
}使用 find() 方法顯示集合中的所有文件。查詢如下所示 −
> db.paginationDemo.find().pretty();
以下是輸出 −
{
"_id" : ObjectId("5c949de44cf1f7a64fa4df52"),
"CustomerName" : "Chris",
"CustomerAge" : 23
}
{
"_id" : ObjectId("5c949df14cf1f7a64fa4df53"),
"CustomerName" : "Robert",
"CustomerAge" : 26
}
{
"_id" : ObjectId("5c949dfc4cf1f7a64fa4df54"),
"CustomerName" : "David",
"CustomerAge" : 24
}
{
"_id" : ObjectId("5c949e3e4cf1f7a64fa4df55"),
"CustomerName" : "Carol",
"CustomerAge" : 28
}
{
"_id" : ObjectId("5c949e474cf1f7a64fa4df56"),
"CustomerName" : "Bob",
"CustomerAge" : 29
}以下是 MongoDB 分頁的查詢 −
> db.paginationDemo.find().skip(0).limit(3);
以下是輸出 −
{ "_id" : ObjectId("5c949de44cf1f7a64fa4df52"), "CustomerName" : "Chris", "CustomerAge" : 23 }
{ "_id" : ObjectId("5c949df14cf1f7a64fa4df53"), "CustomerName" : "Robert", "CustomerAge" : 26 }
{ "_id" : ObjectId("5c949dfc4cf1f7a64fa4df54"), "CustomerName" : "David", "CustomerAge" : 24 }
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