【MongoDB】limit()
limit()，熟悉MySQL的小伙伴应该不陌生，MongoDB的limit()与之相似
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db.collection.find().limit(number) |
1：测试数据
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> db.t.find() { "_id" : ObjectId("5982b8b2c566b07b8733e787"), "a" : 5, "b" : 5, "c" : null } { "_id" : ObjectId("5982b8b2c566b07b8733e788"), "a" : 3, "b" : null, "c" : 8 } { "_id" : ObjectId("5982b8b2c566b07b8733e789"), "a" : null, "b" : 3, "c" : 9 } { "_id" : ObjectId("5982b8b2c566b07b8733e78a"), "a" : 1, "b" : 2, "c" : 3 } { "_id" : ObjectId("5982b8b2c566b07b8733e78b"), "a" : 2, "c" : 5 } { "_id" : ObjectId("5982b8b2c566b07b8733e78c"), "a" : 3, "b" : 2 } { "_id" : ObjectId("5982b8b2c566b07b8733e78d"), "a" : 4 } { "_id" : ObjectId("5982b8b2c566b07b8733e78e"), "b" : 2, "c" : 4 } { "_id" : ObjectId("5982b8b2c566b07b8733e78f"), "b" : 2 } { "_id" : ObjectId("5982b8b3c566b07b8733e790"), "c" : 6 } { "_id" : ObjectId("5982c220c566b07b8733e791"), "a" : "guan", "b" : "yu", "c" : "guanyunchang" } > |
2：limit(1)
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> db.t.find().limit(1) { "_id" : ObjectId("5982b8b2c566b07b8733e787"), "a" : 5, "b" : 5, "c" : null } > |
3：limit()
db.t.find().limit()等价于db.t.find()