5、唯一索引 先看看之前創建的，rsc索引： index --------- { "name" : "rsc_1" , "ns" : "ms_basic.schedule" , "key" : { "rsc" : 1}} 在rsc字段上，創建唯一索引： coll.dropIndex(new BasicDBObject("rsc", 1)); coll.ensureIndex(new BasicDBObject("rsc", 1).append("unique", true)); 顯示結果： index --------- { "name" : "rsc_1_unique_" , "ns" : "ms_basic.schedule" , "key" : { "rsc" : 1 , "unique" : true}} 存在如下rsc=的數據： { "_id" : { "$oid" : "4c2fe764dd969674cb31a0be"} , "liveStatus" : 0 , "startDate" : "2010-11-12" , "isList" : 0 , "location" : "CAG" , "posttime" : "2010-04-01 15:04:57.0" , "rsc" : "WRM160513" , "noliveTvName" : "" , "endDate" : "2010-11-12" , "endTime" : "09:30" , "isGold" : 0 , "version" : 0 , "startTime" : "09:30" , "disciplineName" : "摔跤" , "event" : "160" , "gender" : "M" , "isMedal" : 0 , "discipline" : "WR" , "venueId" : "CAG" , "phaseName" : "資格賽" , "isRecommend" : 0 , "isData" : 0 , "eventUnitType" : "HATH" , "chatroomStatus" : 0 , "isChina" : 0 , "isStartTime" : 0 , "competitionStatus" : 0 , "unit" : "13" , "tvName" : "男子古典式 - 60公斤級資格賽" , "flag" : 0 , "scheduleName" : "資格賽" , "isEndTime" : 0 , "rid" : "" , "eventName" : "男子古典式 - 60公斤級" , "phase" : "5" , "isResult" : 0} 往表data中插入一條記錄。 System.out.println("-----------華麗分隔線---------------");??? ??? Schedule schedule = new Schedule(); ??? schedule.setRsc("WRM160513"); ??? schedule.setScheduleName("重復值"); ??? BasicDBObject val = new BasicDBObject(); ??? val.put("rsc","WRM160513"); ??? val.put("scheuleName","kaokao"); coll.insert(val); 沒有報錯，查詢結果： { "_id" : { "$oid" : "4c2fe764dd969674cb31a0be"} , "liveStatus" : 0 , "startDate" : "2010-11-12" , "isList" : 0 , "location" : "CAG" , "posttime" : "2010-04-01 15:04:57.0" , "rsc" : "WRM160513" , "noliveTvName" : "" , "endDate" : "2010-11-12" , "endTime" : "09:30" , "isGold" : 0 , "version" : 0 , "startTime" : "09:30" , "disciplineName" : "摔跤" , "event" : "160" , "gender" : "M" , "isMedal" : 0 , "discipline" : "WR" , "venueId" : "CAG" , "phaseName" : "資格賽" , "isRecommend" : 0 , "isData" : 0 , "eventUnitType" : "HATH" , "chatroomStatus" : 0 , "isChina" : 0 , "isStartTime" : 0 , "competitionStatus" : 0 , "unit" : "13" , "tvName" : "男子古典式 - 60公斤級資格賽" , "flag" : 0 , "scheduleName" : "資格賽" , "isEndTime" : 0 , "rid" : "" , "eventName" : "男子古典式 - 60公斤級" , "phase" : "5" , "isResult" : 0} 注意：java應用中，有個問題，如果數據已經重復了，那么使用： coll.ensureIndex(new BasicDBObject("rsc", 1).append("unique", true)); 是沒有錯誤提示的，此時繼續執行插入操作，是成功的。 { "_id" : { "$oid" : "4c2fe764dd969674cb31a0be"} , "liveStatus" : 0 , "startDate" : "2010-11-12" , "isList" : 0 , "location" : "CAG" , "posttime" : "2010-04-01 15:04:57.0" , "rsc" : "WRM160513" , "noliveTvName" : "" , "endDate" : "2010-11-12" , "endTime" : "09:30" , "isGold" : 0 , "version" : 0 , "startTime" : "09:30" , "disciplineName" : "摔跤" , "event" : "160" , "gender" : "M" , "isMedal" : 0 , "discipline" : "WR" , "venueId" : "CAG" , "phaseName" : "資格賽" , "isRecommend" : 0 , "isData" : 0 , "eventUnitType" : "HATH" , "chatroomStatus" : 0 , "isChina" : 0 , "isStartTime" : 0 , "competitionStatus" : 0 , "unit" : "13" , "tvName" : "男子古典式 - 60公斤級資格賽" , "flag" : 0 , "scheduleName" : "資格賽" , "isEndTime" : 0 , "rid" : "" , "eventName" : "男子古典式 - 60公斤級" , "phase" : "5" , "isResult" : 0} { "_id" : { "$oid" : "4c3334ea76c7eebe35fb1f81"} , "rsc" : "WRM160513" , "scheduleName" : "kaokao"} java中，生成索引結果： > db.schedule.getIndexes(); [ ??????? { ??????????????? "name" : "_id_", ??????????????? "ns" : "ms_basic.schedule", ??????????????? "key" : { ??????????????????????? "_id" : 1 ??????????????? } ??????? }, ??????? { ??????????????? "name" : "rsc_1_unique_", ??????????????? "ns" : "ms_basic.schedule", ??????????????? "key" : { ??????????????????????? "rsc" : 1, ??????????????????????? "unique" : true ??????????????? } ??????? } ] 命令行結果： > db.schedule.ensureIndex({rsc:1},{unique: true}); > db.schedule.getIndexes(); [ ??????? { ??????????????? "name" : "_id_", ??????????????? "ns" : "ms_basic.schedule", ??????????????? "key" : { ??????????????????????? "_id" : 1 ??????????????? } ??????? }, ??????? { ??????????????? "_id" : ObjectId("4c3335de22090000000065d5"), ??????????????? "ns" : "ms_basic.schedule", ??????????????? "key" : { ??????????????????????? "rsc" : 1 ??????????????? }, ??????????????? "name" : "rsc_1", ??????????????? "unique" : true ??????? } ] 后來檢查發現： 應該使用：coll.ensureIndex(new BasicDBObject("rsc", 1),"rsc",true); 而不是：coll.ensureIndex(new BasicDBObject("rsc", 1).append("unique", true)); 這種方式相當于創建了組合索引：rsc_unique，是錯誤的 認真看看API文檔說明即可發現。

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