MongoDB是基于分布式文件存储的数据库,本文将介绍如何对MongoDB记录中集合字段进行匹配查询。
use testdb db.createUser( { "user":"root", "pwd":"123456", "roles":[{"role" : "readWrite", "db":"testdb"}] } ) db.auth( { "user":"root", "pwd":"123456" } )
db.member.insert([ { "id" : 1, "name" : "fdipzone", "area_id" : [1,2,3], }, { "id" : 2, "name" : "tom", "area_id" : [3,4], }, { "id" : 3, "name" : "polly", "area_id" : [1,3,7], }, { "id" : 4, "name" : "anslem", "area_id" : [2,4,6], }, { "id" : 5, "name" : "terry", "area_id" : [4,5,9], } ])
查询插入的数据
db.member.find(); { "_id" : ObjectId("59f589f5641e44b4c51cb770"), "id" : 1, "name" : "fdipzone", "area_id" : [ 1, 2, 3 ] } { "_id" : ObjectId("59f589f5641e44b4c51cb771"), "id" : 2, "name" : "tom", "area_id" : [ 3, 4 ] } { "_id" : ObjectId("59f589f5641e44b4c51cb772"), "id" : 3, "name" : "polly", "area_id" : [ 1, 3, 7 ] } { "_id" : ObjectId("59f589f5641e44b4c51cb773"), "id" : 4, "name" : "anslem", "area_id" : [ 2, 4, 6 ] } { "_id" : ObjectId("59f589f5641e44b4c51cb774"), "id" : 5, "name" : "terry", "area_id" : [ 4, 5, 9 ] }
查询area_id含有1的记录
db.member.find({"area_id":{$in:[1]}}); { "_id" : ObjectId("59f589f5641e44b4c51cb770"), "id" : 1, "name" : "fdipzone", "area_id" : [ 1, 2, 3 ] } { "_id" : ObjectId("59f589f5641e44b4c51cb772"), "id" : 3, "name" : "polly", "area_id" : [ 1, 3, 7 ] }
注意,$in只能检查集合内每一个元素是否匹配,只要任意一个匹配就返回记录,并不能检查同时匹配多个元素的情况。
例如要查询area_id同时包含2和4的记录,使用$in只会查询出含有2或4的记录。
db.member.find({"area_id":{$in:[2,4]}}); { "_id" : ObjectId("59f58ddfa874fe2b3da340bf"), "id" : 1, "name" : "fdipzone", "area_id" : [ 1, 2, 3 ] } { "_id" : ObjectId("59f58ddfa874fe2b3da340c0"), "id" : 2, "name" : "tom", "area_id" : [ 3, 4 ] } { "_id" : ObjectId("59f58ddfa874fe2b3da340c2"), "id" : 4, "name" : "anslem", "area_id" : [ 2, 4, 6 ] } { "_id" : ObjectId("59f58ddfa874fe2b3da340c3"), "id" : 5, "name" : "terry", "area_id" : [ 4, 5, 9 ] }
$all可以检查同时匹配多个元素的情况
查询area_id同时含有2和4的记录
db.member.find({"area_id":{$all:[2,4]}}); { "_id" : ObjectId("59f58ddfa874fe2b3da340c2"), "id" : 4, "name" : "anslem", "area_id" : [ 2, 4, 6 ] }