MongoDB中使用find來(lái)進(jìn)行查詢,返回一個(gè)集合中的文檔的子集;
返回文檔集合blog中的所有文檔:
> db.post.find() { "_id" : ObjectId("54a530c3ff0df3732bac1681"), "id" : 2, "name" : "joe", "age" : 30, "sex" : 1, "school" : "marry" } { "_id" : ObjectId("54a530c3ff0df3732bac1680"), "id" : 1, "name" : "joe", "age" : 30, "comments" : [ "test2", "test9", "test5" ], "sex" : 1, "school" : "marry" } >返回指定的文檔:
> db.post.find({"id":1}) { "_id" : ObjectId("54a530c3ff0df3732bac1680"), "id" : 1, "name" : "joe", "age" : 30, "comments" : [ "test2", "test9", "test5" ], "sex" : 1, "school" : "marry" } >返回指定的鍵值:
> db.post.find({},{"id":1,"age":1}) { "_id" : ObjectId("54a530c3ff0df3732bac1681"), "id" : 2, "age" : 30 } { "_id" : ObjectId("54a530c3ff0df3732bac1680"), "id" : 1, "age" : 30 } >默認(rèn)總是會(huì)返回“_id”鍵,使用下面的方法可以不返回“ _id”鍵:
> db.post.find({},{"id":1,"age":1,"_id":0}) { "id" : 2, "age" : 30 } { "id" : 1, "age" : 30 } >可以將多個(gè)條件組合在一起,例如查詢名字為“Joe”且ID為1的文檔:
> db.post.find({"name":"joe"}) { "_id" : ObjectId("54a530c3ff0df3732bac1681"), "id" : 2, "name" : "joe", "age" : 30, "sex" : 1, "school" : "marry" } { "_id" : ObjectId("54a530c3ff0df3732bac1680"), "id" : 1, "name" : "joe", "age" : 30, "comments" : [ "test2", "test9", "test5" ], "sex" : 1, "school" : "marry" } > db.post.find({"name":"joe","id":1}) { "_id" : ObjectId("54a530c3ff0df3732bac1680"), "id" : 1, "name" : "joe", "age" : 30, "comments" : [ "test2", "test9", "test5" ], "sex" : 1, "school" : "marry" } >另外有需要云服務(wù)器可以了解下創(chuàng)新互聯(lián)cdcxhl.cn,海內(nèi)外云服務(wù)器15元起步,三天無(wú)理由+7*72小時(shí)售后在線,公司持有idc許可證,提供“云服務(wù)器、裸金屬服務(wù)器、高防服務(wù)器、香港服務(wù)器、美國(guó)服務(wù)器、虛擬主機(jī)、免備案服務(wù)器”等云主機(jī)租用服務(wù)以及企業(yè)上云的綜合解決方案,具有“安全穩(wěn)定、簡(jiǎn)單易用、服務(wù)可用性高、性價(jià)比高”等特點(diǎn)與優(yōu)勢(shì),專為企業(yè)上云打造定制,能夠滿足用戶豐富、多元化的應(yīng)用場(chǎng)景需求。