nosql

Firestore - How to model and query relation of 2 collections - IOT use case - v2

由 ℡╲_俬逩灬. 提交于 2019-12-11 15:53:05
问题 extending to my question Firestore - How to model and query relation of 2 collections - IOT use case I'ved now seen a video on this, and this recommends modelling relations using document ID. https://www.youtube.com/watch?v=jm66TSlVtcc skip to 6:07 I want to know if it would work in this case (modifying the example from my original question to fit to this youtube recommendation of firestore relation: Eg: I have 2 different collection - tracking and venue tracking <-- collection 1. document

Redis

由 喜欢而已 提交于 2019-12-11 15:49:08
目录 Redis 优势 与其他key-value存储的不同 Redis和MySQL的区别 总结 Redis的安装 Rdis键语法 Redis哈希 Redis Redis是完全开源免费的，遵守BSD协议，是一个高性能的key-value数据库 Redis支持数据的持久化，可以将内存中的数据保存在磁盘中，重启的时候可以再次加载使用 Redis不仅支持key-value类型的数据，同时还提供list、set、zset、hash等数据结构的存储 Redis支持数据的备份，即master-slave模式的数据备份 优势 性能极高，redis能读的速度是11w次/s，写的速度是8.1w次/s 丰富的数据类型，Redis支持二进制案例的Strings、Lists、Hashes、Sets及Ordered Sets数据类型操作 原子，Redis的所有操作都是原子性的，就是要么成功执行所有操作要么完全失败不执行，单个操作是原子性的。多个操作也支持事务，通过MULIT和EXEC指令包起来 丰富的特性，Redis还支持publish/subscribe，通知，key过期等特性 与其他key-value存储的不同 Redis有着更为复杂的数据结构并且提供对他们的原子性操作；Redis的数据类型都是基于基本数据结构的同时对程序员透明，无需进行额外的抽象 Redis运行在内存中但是可以持久化到硬盘

You have defined query method in the repository but you don't have any query lookup strategy defined

由 心不动则不痛 提交于 2019-12-11 15:42:21
问题 Yesterday this solution was working fine. Today I woke up to rerun the tests & it failed stating in the stacktrace that You have defined query method in the repository but you don't have any query lookup strategy defined. The infrastructure apparently does not support query methods! at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.(RepositoryFactorySupport.java:533) As clearly shown I did not define any query methods. :-( I'm stuck, I

Firestore - How to model and query relation of 2 collections - IOT use case

由 时光毁灭记忆、已成空白 提交于 2019-12-11 15:35:39
问题 Would it be possible to do relation in this sense in firestore ? whereby I want to relate a field in collection to another field in another collection Eg: I have 2 different collection - tracking and venue tracking <-- collection 1. document(xyz123) device_unique_identifier = "abcd1234" timestamp = 10/09/2019 10:00 2. document(xyz567) device_unique_identifier = "efgh3456" timestamp = 10/09/2019 11:00 venue <-- collection 1. document(zyx123) name = "room A" device_unique_identifier = "abcd1234

Add dynamically created attributes in ressource

由 时光总嘲笑我的痴心妄想 提交于 2019-12-11 15:14:45
问题 I'm working on a project in Laravel where for persistance i'm using a nosql graph based database called neo4j .The thing is that,for a given model,for some reasons the app admin can create new fields in the UI and give the names and validation rules.That means a part from attributes defined in $fillable attributes,new fields are added dynamically.And to manage that,i've created a flexible validation rule for the given model to updated dynamically validation rules by considering new fields,and

ElasticSearch : plain text file instead of JSON

由 北战南征 提交于 2019-12-11 15:02:55
问题 Interested in elasticsearch and working with txt files not json. Can elasticsearch support plain text file? If yes, Is there any java API, I can use ( I tested crud operations with postman on JSON document and it's working fine ) Thanks for the help. 回答1: No, the elasticsearch document api supports only JSON. But there is a workaround for this problem using ingestion pipelines running on ingestion nodes in your cluster https://www.elastic.co/guide/en/elasticsearch/reference/current/ingest

Materialised view error in Cassandra

由 徘徊边缘 提交于 2019-12-11 14:52:31
问题 I am new to Cassandra, I am trying to create a table and materialized view. but it not working. My queries are: -- all_orders create table all_orders ( id uuid, order_number bigint, country text, store_number bigint, supplier_number bigint, flow_type int, planned_delivery_date timestamp, locked boolean, primary key ( order_number,store_number,supplier_number,planned_delivery_date )); -- orders_by_date CREATE MATERIALIZED VIEW orders_by_date AS SELECT id, order_number, country, store_number,

How to create equivalent view in cloudant for distinct and cout query in mysql

由 两盒软妹~` 提交于 2019-12-11 14:31:47
问题 I have 1000 documents of type below and I want to design a document in cloudant (write a view) equivalent to this Mysql query: (SELECT COUNT(DISTINCT(correlationassetid)), PERIOD FROM view_asset WHERE ((PERIOD >= '201705') AND (PERIOD <= '201705')) GROUP BY PERIOD ORDER BY PERIOD ASC) I have tried below view but it does not give proper result. could any one help me? function (doc) { if(doc.type == "asset"){ emit(doc.period,1); } { "_id": "24dee0ec910e22605fe8fc4189000c56", "_rev": "1

Composite views in couchbase

由 倾然丶 夕夏残阳落幕 提交于 2019-12-11 14:05:48
问题 I'm new to Couchbase and am struggling to get a composite index to do what I want it to. The use-case is this: I have a set of "Enumerations" being stored as documents Each has a "last_updated" field which -- as you may have guessed -- stores the last time that the field was updated I want to be able to show only those enumerations which have been updated since some given date but still sort the list by the name of the enumeration I've created a Couchbase View like this: function (doc, meta)

error LNK2019: unresolved external symbo UnQLite

由 五迷三道 提交于 2019-12-11 13:43:40
问题 I am trying to use UnQLite database with visual studio 2012, but when I try to open the database I got the following error: error LNK2019: unresolved external symbol "int __cdecl unqlite_open(struct unqlite * *,char const *,unsigned int)" (?unqlite_open@@YAHPAPAUunqlite@@PBDI@Z) referenced in function "bool __cdecl connect_database(void)" (?connect_database@@YA_NXZ) This is my code: void connect_database() { // Open our database; rc = unqlite_open(&pDb,"myDB.db",UNQLITE_OPEN_CREATE); if( rc !
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