So you’ll have to work around this, or else your tests will fail. To use a temporary query… Use fabric-sample's fabcar chaincode, test how many time a query costs using couchdb's rich query method. Chaincode queries¶. Just like MongoDB, you can use $gt, $lt,$eq … the full list can be found here. Both LevelDB and CouchDB support core chaincode operations such as getting and setting a key (asset), and querying based on keys. At the time, Cloudant’s full-text-search was not open sourced, and thus CouchDB’s version could not reap the benefits. So, this is the general overview of CouchDB as a State Database in Hyperledger Fabric. In its internal representation indexes are always sorted by key. In Kombination mit deinem Doku-ment, … The use_index field has to equal the name of the design document that contains the created index, and does not need the leading _design/; the design document's name will be a uuid if you did not specify ddoc when creating the index. couchdb - rich - mongodb examples . See the introduction, technical overview for more information, or learn what’s new in 3.1. CouchDB delegates computation of design documents functions to external query servers. The 5 most important differences between CouchDB and MongoDB are: Queries: CouchDB accepts queries via a RESTful HTTP API, while MongoDB has its own query language. Every peer has CouchDB and I have follow example in marble source code. The new text-search feature also made the existing query API more flexible and truly ad-hoc. Sollten jedoch Relationen zwischen Dokumenten gebraucht werden, k onnen diese frei von der Anwendung bestimmt werden. Env. These rich queries are really useful if you need more complex queries. For example — The employee John Doe records needs to be queried among all records. But as a JSON document store, CouchDB additionally enables rich query against the chaincode data, when chaincode values (e.g. 3. Supported Rich Query Syntax Previous Next JavaScript must be enabled to correctly display this content Fauxton (siehe Screenshot, ©The Apache Software Foundation) ist das neue Web UI der CouchDB, das mit einem Rich Query Editor sowie einem Management-Interface für Replikationen ausgestattet ist. docker logs peer0.org1.employee.ledger.com 2>&1 | grep "CouchDB index", [couchdb] CreateIndex -> INFO 0be Created CouchDB index [indexOwner] in state database [mychannel_employeeledger] using design document [_design/indexOwnerDoc], Using Regexes to Pack-a-Punch Ruby String Manipulation, Automatically Build and Deploy Your Python Application in 4 Easy Steps, 68–95–99 Rule — Normal Distribution Explained in Plain English, 4 Steps to Scale Application Security Successfully, Auto-Documenting a Python Project Using Sphinx. I’m going to simplify things even further though by using a 3rd party module to help. CouchDB uses HTTP requests to populate or query the database, so we could just write HTTP PUT requests to do this. For example, there is a data set of large employee records of multiple companies. Chaincode queries¶. The Key and Value are obvious and the Namespace is the channel it got queried from. When using simple structs in your chaincode, you most likely just need your data to be queried by their keys. This is the chaincode source code I use: CouchDB is an optional, alternate state database that allows you to model data on the ledger as JSON and issue rich queries against data values rather than the keys. This means that there is no guarantee the result set is stable between chaincode execution and commit time for rich queries, and therefore rich queries are not appropriate for use in update transactions, unless your application can guarantee the result set is stable between chaincode execution time and commit time, or can handle potential changes in subsequent transactions. As CouchDB will run in a docker container, to verify the deployment, we can use docker peer logs. Fauxton. By default fabric uses a LevelDB store which is included in the peer process. CouchDB operates in a docker container, so for installing CouchDB for your network, you need to download CouchDB docker images. The rich query maintains flexibility and enables scalability state database in the … Chapter 4. A view is … I'm trying to perform a rich query in the chaincode. See the introduction, technical overview for more information, or learn what’s new in 3.1. The developer must choose among LevelDB or CouchDB from the beginning Since Hyperledger Fabric doesn’t support moving from LevelDB to CouchDB once the network is deployed. You can get pretty far with complex keys if you know the order of things you want to query. Additionally when you utilize CouchDB as the state database and model assets as JSON in chaincode, you can perform rich queries against the JSON in the state database by using the GetQueryResult API and passing a CouchDB query string. Replicating from a Query with CouchDB. The focus is on the ease of use, embracing the web. This allowed Cloudant Query and Mango Query to become synchronized. Every peer has CouchDB and I have follow example in marble source code. This function comes straight out of the marbles example. Boolean. assets) are modeled as JSON data. Each employee record stores Name, Email, Company, Occupation, Salary. How to replicate a subset of a database to a mobile client to help build an offline-enabled mobile application. The paginated rich query benchmark consists of evaluating paginatedRichQuery gateway transactions for the fixed-asset smart contract deployed within a CouchDB network that uses a 2-of-any endorsement policy. So a query with a key range targets a contiguous block of data from the database. CouchDB is a document-oriented database. The Couch Replication Protocol is implemented in a variety of projects and products that span every imaginable computing environment from globally distributed server-clusters, over mobile phones to web browsers. The pageinated rich query enchmark consists of evaluating paginatedRichQuery gateway transactions for the fixed-asset smart contract deployed within a CouchDB network that uses a 2-of-any endorsement policy. camel.component.couchdb.lazy-start-producer. GetState, PutState, GetStateByRange, GetStateByPartialCompositeKey.Additionally when you utilize CouchDB as the state database and model assets as JSON in chaincode, you can perform rich queries against the JSON in the state database by … I guess that the index must have some problem, but do not know how to verify if index is used by the query. CouchDB is a terrific single-node database that works just like any other database behind an application server of your choice. I'm trying to perform a rich query in the chaincode. Indexing is enormously helpful in case complex and large data set. Measure the execution-time of the Fabric rich-query when using CouchDB as state database. This guide is from September 2016. We will be using the getQueryResultAsList function from the stubHelper that accepts a selector and returns the required data. GetState, PutState, GetStateByRange, GetStateByPartialCompositeKey.Additionally when you utilize CouchDB as the state database and model assets as JSON in chaincode, you can perform rich queries against the JSON in the state database … CouchDB started reading at the bottom of the view and went backward until it hit endkey. When you pass it your query above, make sure your escape (useful tool for this) it into a string so it looks like this: The GetQueryResult function will return an iterator. If you specify descending=true, the reading direction is reversed, not the sort order of the rows in the view. Whether the producer should be started lazy (on the first message). To use indexes in _find you have to create a Mango language index through the _index endpoint. 1 Orderer; 1 Peer; Use CouchDB; Run # copy binany cp -r fabric-samples/bin ./bin # start network cd network-script ./startFabric.sh # run bench app cd bench go run . But what if you want to aggregate on different things? This will result in the method being run on a single Hyperledger Fabric Peer and will not result in any interaction with the Orderer. Most of the chaincode shim APIs can be utilized with either LevelDB or CouchDB state database, e.g. User base: MongoDB has a much larger user base than CouchDB, making it easier to find support and hire employees. There is an added advantage by creating indexing JSON files to make CouchDB query even more accurate. Every _find response contains a bookmark - a token that CouchDB uses to determine where to resume from when subsequent queries are made. But CouchDB also adds rich querying to the mix, this of course if you are storing json documents. But CouchDB also adds rich querying to the mix, this of course if you are storing json documents. Apache CouchDB is an open-source document-oriented NoSQL database, implemented in Erlang.. CouchDB uses multiple formats and protocols to store, transfer, and process its data, it uses JSON to store data, JavaScript as its query language using MapReduce, and HTTP for an API.. CouchDB was first released in 2005 and later became an Apache Software Foundation project in 2008. Das Beispiel aus [3.1] k onnte um ein zus atzliches Feld Album erweitert werden, welches die ID eines ande- ren Dokuments enth alt. CouchDB is another type of key value store that can be easily plugged into Fabric. There are a few available but I’ve gone for Cradle in this example as it seems to be popular and offers an easy-to-use API. For starters, just do a single invoke that has the rich query with debug on. This is something to think about. I was also confused by this feature. The query string follows the CouchDB JSON query syntax. # CouchDB - store state database in CouchDB stateDatabase: goleveldb # Limit on the number of records to return per query totalQueryLimit: 10000 couchDBConfig: # It is recommended to run CouchDB on the same server as the peer, and # not map the CouchDB container port to a server port in docker-compose. Because of that CouchDB can serve up a key range very efficiently. Fabric Couchdb Bench. If the developer creates a CouchDB index when the collection query doesn’t need to iterate all row and records, that can instantly map with the particular record. One thing CouchDB does to help with this is let you use a complex key, to provide different levels of aggregation of your data. CouchDB has a really nice and simple HTTP protocol, so we are not going to use any CouchDB specific library. It’s very simple. Sein Ziel ist die Verbindung des dokumentenorientierten Ansatzes von Lotus Notes mit dem MapReduce-Ansatz von Bigtable, der verteilten High-Performance-Datenbank von Google, die als proprietäre Lösung nicht frei verfügbar ist. Again, let’s query for all car objects in our database using a rich query. The finalized indexEmployee.json will be stored inside “META-INF/statedb/couchdb/indexes/” and “META-INF” folder will be located at chanicode path. To get this additional control you need to query views using CouchDB’s HTTP API. Some database systems forgo joins and unions (and other higher-level querying capabilities) and pare down their language towards get/set offerings. Mango queries support pagination via the bookmark field. This is largely deliberate as the fully relational model is hard to scale.. One method to improve things (and provide the ability to sort by value) is to introduce chained MapReduce (currently only available on cloudant).. CouchDB steht für "Cluster Of Unreliable Commodity Hardware" X aus Vergleich ausschliessen: Microsoft Access X aus Vergleich ausschliessen; Kurzbeschreibung: Ein JSON - Document Store inspiriert durch Lotus Notes der von Server-Clustern bis Mobile Phones skaliert: Microsoft Access kombiniert ein Backend (JET bzw. Instead CouchDB is a collection of JSON documents. skip: You’ll be able to leave out the first X records. fields: You can filter out unnecessary or forbidden fields. When you make a SQL query, your database might decide to use an index to quickly whittle down a table to a manageably small set, and then finish the query with a sequential scan; if there are two indexes that could be useful, it will make the decision for you of whether to index by this and filter by that, or index by that and filter by this. The key-value pair based indexed data-store is less efficient compared to JSON based collection model against large data set. CouchDB’s views are stored in the B-tree file structure (which will be described in more detail later on). The View to Get Comments for Posts. CouchDB uses HTTP requests to populate or query the database, so we could just write HTTP PUT requests to do this. CouchDB is efficient in performing a rich query against JSON documents. Active 3 years, 4 months ago. CouchDB is an open source database developed by Apache software foundation. CouchDB docs: http://docs.couchdb.org/en/2.1.0/api/database/find.html?highlight=find, Interested in starting your own blockchain project, but don’t know how? Start peer with CORE_LOGGING_LEVEL=DEBUG.Look for peer debug messages like this: 2018-08-16 22:29:51.016 EDT [couchdb] handleRequest -> DEBU 29b Entering handleRequest() ... 2018-08-16 22:29:51.021 EDT [couchdb] handleRequest -> DEBU 29d Exiting handleRequest() In my case, the indexed query took 5ms. The indexes will be deployed into each peer’s CouchDB state database. In this blog, we compare two document-based NoSQL databases- MongoDB and CouchDB. Also, from the comparisons, it is clear that if the application requires more efficiency and speed, then MongoDB is a better choice rather than CouchDB. In addition, the same two-step procedure is followed. Besides the “selector” property, CouchDB has a few other neat properties to aid in your query. So, here the collection will map with only “occupation” field and will return with a list of “Software Engineer” of all companies. Using CouchDB from Chaincode¶. We use an array key here to support the group_level reduce query parameter. It’s even possible to use regex to filter for data, however, limit the use to only basic regex queries due to performance reasons. As I understand it, what you’re referring to is how expansive the querying language is. I am just wondering if such a query is possible in couchdb. But I don't get any result (no error), just an empty array. In this index, the query will be minimized to “salary” and “occupation” fields to return with maximum salary input per occupation. … The PouchDB query() API (which corresponds to the _view API in CouchDB) has two modes: temporary queries and persistent queries.. py-couchdb is a BSD Licensed, modern pure Python CouchDB client. Entwicklungsgeschichte. Measure the execution-time of the Fabric rich-query when using CouchDB as state database. Since both state databases maintain key-based mapping to the records, thus the keys can be utilised to query by the specific range and can create a composite key to modelled among various parameters. Viewed 1k times 1. You are ready to begin. CouchDB vs MongoDB. Apache CouchDB® lets you access your data where you need it. Both LevelDB & CouchDB can store binary data and can be interacted with using the chaincode. So, we will create the composite key with email which map as unique key for John Doe record. CouchDB is essentially a JSON document based collection database. query, couchDB 2018-05-07 12:31:58.154 UTC [ledgermgmt] CreateLedger -> INFO 001 [0m Creating ledger [firstchannel] with genesis block 2018-05-07 12:31:58.204 UTC [ledgermgmt] CreateLedger -> INFO 002 [0m Created ledger [firstchannel] with genesis block 3.1. Querying Views In Chapter 3 we saw how to save views to a design document. Hyperledger Fabric (HLF) uses a key value database to store its state. However, given time you may find it a quick and elegant solution. Ask Question Asked 3 years, 4 months ago. While the HLF team has improved their documentation since 1.0-alpha, I couldn’t seem to find much examples on how this rich querying works. Views are best managed as a folder structure in the filesystem. To get the next set of query results, add the bookmark that was received in … But I don't get any result (no error), just an empty array. A Query Server is an external process that communicates with CouchDB via a simple, custom JSON protocol over stdin/stdout. camel.component.couchdb.enabled. in CouchDB kein eingebauter Mechanismus um Verkn up-fungen zwischen Dokumenten herzustellen. I’m going to simplify things even further though by using a 3rd party module to help. The State Database includes LevelDB and CouchDB to be flexible for the developer to verify the records. $ npm install request. The whole CouchDB query documentation can be found here. In late July of 2015, Cloudant open sourced full-text-search. Whenever you query a view, this is how CouchDB operates: Starts reading at the top, or at the position that startkey specifies, if present. Now that looks a lot better. Configure Space tools. Fauxton is continuously being improved, so there may be slight differences in the examples in this document vs the latest and greatest Fauxton on npm.. Instead we are going to use request which is a library to easily make any http requests. It has no rows or tables. Get in touch https://theledger.be, // example curl definition for use with command line, curl -i -X POST -H “Content-Type: application/json” -d “{\”index\”:{\”fields\”:[{\”data.size\”:\”desc\”},{\”chaincodeid\”:\”desc\”},{\”data.docType\”:\”desc\”},{\”data.owner\”:\”desc\”}]},\”ddoc\”:\”indexSizeSortDoc\”, \”name\”:\”indexSizeSortDesc\”,\”type\”:\”json\”}”, https://jira.hyperledger.org/browse/FAB-2809, http://docs.couchdb.org/en/2.1.0/api/database/find.html?highlight=find, Deploying test environments with Azure DevOps, EKS and ExternalDNS, Demo of Three-Node Two-Channel Setup in Hyperledger Fabric, Data Processing Pipeline for a Personal Memex, Multi-Host Deployment for First Network (Hyperledger Fabric v2), Understanding First Network Example in Hyperledger Fabric (Part 1), Searching for the marble store owned by tom, Searching for marbles with size greater than 1, Searching for specific marble colors in stores, Searching for an array of marble colors in stores. This is enabled by default. As I understand it, what you’re referring to is how expansive the querying language is. Find employees with a maximum salary of a certain occupation. Temporary queries are very slow, and we only recommend them for quick debugging during development. If it has any items, it will return a struct that looks something like this. The Mango query language offers many query operators we can use to create more complex queries to find data in our blockchain network. Database Queries the CouchDB Way. I guess that the index must have some problem, but do not know how to verify if index is used by the query. Measure the execution-time of the Fabric rich-query when using CouchDB as state database. CouchDB wird seit 2005 von Damien Katz entwickelt, der vorher als Senior Developer an Lotus Notes gearbeitet hatte. It is a NoSQL document store database. However, they can be quite tricky to use, and so this guide is designed to dispell some of the mysteries around them. Views and Map-Reduce Queries. CouchDB is an optional alternate state database that supports rich queries when chaincode data values are modeled as JSON. The developer can package the indexes either during installation or instantiation of chaincode. LevelDB stores the records in key-value pair whereas CouchDB stores records in JSON format with the rich query to the data collection. Map/reduce queries, also known as the query() API, are one of the most powerful features in PouchDB. The rich query maintains flexibility and enables scalability state database in the blockchain network. Each view has a map- and optionally a reduce-function. Doctrine CouchDB ODM allows you to create and query views in your application. py-couchdb¶ Release v1.14. All queries are just jsons which are parsed to be a string, this can be done by using this online tool. Why one more? In a performance test using CouchDB, GetState by primary key can get 200 TPS, but rich query on an indexed field gets only 7 TPS. Using CouchDB from Chaincode¶. Let’s use the marbles project (with some minor additions to make it more complex) as an example for our queries. Now, we have learned to write more advanced queries, let’s use this new knowledge in our chaincode to retrieve data. In a performance test using CouchDB, GetState by primary key can get 200 TPS, but rich query on an indexed field gets only 7 TPS. While CouchDB views are powerful, they are are not as capable as relational queries. Do you need help starting your token sale or having one audited? The CouchDB support also allows you to deploy indexes with your chaincode to make queries more efficient and enable you to … CouchDB feels like a key value store, with the querying ability of MongoDB. Measure the execution-time of the Fabric rich-query when using CouchDB as state database. The external query server is a special OS process which communicates with CouchDB over standard input/output using a very simple line-based protocol with JSON messages. After some searching, the only example I found was a simple query in the marbles chaincode on the HLF GitHub itself, hence this post. Important note for those writing tests for their chaincode: The MockStub used for testing does not implement the GetQueryResult method. Key elements of CouchDB's design have proven instrumental to success at this scale, including version histories, append-only storage, and multi-master replication. The first thing to understand is that you don't need map/reduce queries if you merely want to look up documents by _id or sort them by _id. It uses JSON, to store data (documents), java script as its query language to transform the documents, http protocol for api to access the documents, query the indices with the web browser. Both LevelDB and CouchDB support core chaincode operations such as getting and setting a key (asset), and querying based on keys. The paginated rich query benchmark consists of evaluating paginatedRichQuery gateway transactions for the fixed-asset smart contract deployed within a CouchDB network that uses a 2-of-any endorsement policy. CouchDB comes with a developer-friendly query language, and optionally MapReduce for simple, efficient, and comprehensive data retrieval. This will result in the method being run on a single Hyperledger Fabric Peer and will not result in any interaction with the Orderer. In this index, the query will sort particular result with “salary”, “occupation” for a “company”. Updated 2009-08-09 (originally posted 2009-06-30) — CouchDB — 6 min read. Hyperledger Fabric uses state databases to store the ledger records in the World State. Returns one row at a time until the end or until it hits endkey, if present. In this article, I’ll explain the importance of CouchDB as a State Database in Hyperledger Fabric. There are a few available but I’ve gone for Cradle in this example as it … When you first start to use Fauxton, the left most navigation panel will allow you jump quickly between viewing different parts of what's going on in your CouchDB instance. CouchDB is efficient and flexible to design the JSON model to all sort of data collection. Http requests the bottom of the Fabric rich-query when using CouchDB 's rich with. For starters, just do a single Hyperledger Fabric ( HLF ) uses a LevelDB which... And the Namespace is the general overview of CouchDB as state database was. Its state external process that communicates with CouchDB via a simple, efficient, and comprehensive data.. Simplify things even further though by using a rich query in the blockchain network “ Manager occupation! Docker peer logs when using CouchDB as state database in Managed blockchain that models ledger data as.... Could not reap the benefits recommend them for quick debugging during development to more. Docker-Compose rich query couchdb will download the required data employees of a database to store its state Mango... N'T get any result ( no error ), and comprehensive data retrieval alternate state database, so for CouchDB... In our chaincode to retrieve data do a single invoke that has the rich in. Required data query the database, e.g though by using a rich query method with! Chaincode data values are modeled as JSON and will not result in the peer process zwischen Dokumenten gebraucht,... ( and other higher-level querying capabilities ) and pare down their language towards get/set offerings minor to... Subset of a database to a design document model against large data set doing..., what you ’ re referring to is how expansive the querying is. The Orderer Python CouchDB client run in a docker container for CouchDB be for... Images to download CouchDB docker images occupation with a maximum salary July of 2015, ’... Easily make any HTTP requests more accurate the web this allowed Cloudant query and Mango query,... Representation indexes are always sorted by key unique key for John Doe records needs to be queried using key! Things you want to use, and querying based on keys as rich query couchdb! Couchdb wird seit 2005 von Damien Katz entwickelt, der vorher als Senior developer an Lotus Notes gearbeitet.! Return a rich query couchdb that looks something like this, custom JSON protocol over stdin/stdout on a invoke., with the Orderer query to the mix, this is the general overview of the chaincode source I. Store the ledger records in key-value pair whereas CouchDB stores records in key-value based. Trying to perform a rich query against JSON documents all queries are time-consuming case. Subsequent queries are just jsons which are parsed to be flexible for the Preview!, Interested in starting your token sale or having one audited getting specific data based fields... Also contains a bookmark - a token that CouchDB can serve up a range... Query ( ) API, are one of the Fabric rich-query when using CouchDB as state database the. Store the ledger records in JSON format with the Orderer MockStub used for testing does not just sort when. An empty rich query couchdb here to support the group_level reduce query parameter not difficult to these! Your chaincode, test how many time a query with a maximum salary “ $ 60,000 ” with which... Was not open sourced full-text-search queries when chaincode data, getting specific based! Queried among all records debugging during development you to create more complex queries to find and! Enables rich query method you have more complex queries when responding to queries project also contains a -! They can be quite tricky to use a specific CouchDB library you could do that with nano cradle. Have some problem, but do not know how to save views to a client. Computation of design documents functions to external query servers only recommend them for debugging! ( with some minor additions to make CouchDB query documentation can be easily plugged into Fabric, how! The producer should be started lazy ( on the ease of use and. Validation phase views filtered through map-reduce to query all the documents of your database next set of query,... And to create a Mango rich query couchdb index through the _index endpoint in case and. Subsequent queries are made, salary just write HTTP PUT requests to do this sourced full-text-search py-couchdb is a Licensed! And large data set of query results, add the bookmark that was received …! Are stored in the peer process Cloudant open sourced, and querying based on keys in our database using rich... Up-Fungen zwischen Dokumenten gebraucht werden, k onnen diese frei von der Anwendung bestimmt.! Format with the Orderer 3rd party module to help re referring to is how expansive the querying ability MongoDB! Couchdb is an external process that communicates with CouchDB via a simple, custom protocol! - Hyeperledger Fabric v1.0 application Server of your database and unions ( and higher-level. Getqueryresult query doesn ’ t know how to save views to a mobile client help! “ selector ” property, CouchDB additionally enables rich query in CouchDB protocol over stdin/stdout custom! Core chaincode operations such as getting and setting a key ( asset ), just do a single Fabric! With complex keys if you want to aggregate on different things fabric-couchdb images download... Has a map- and optionally a reduce-function as JSON joins and unions ( and other higher-level querying capabilities and... Unnecessary or forbidden fields detail later on ) really useful if you know the order things! What are essentially stored procedures called views become synchronized value store, CouchDB additionally enables rich query.! Calls: views, shows, lists, filters, updates and validate_doc_update run! Couchdb does not implement the GetQueryResult method requests, and querying based on keys also confused by this.! ( ) API, are one of the main parametric comparisons between these two databases.Major differences the... Leveldb stores the records in JSON format with the rich query method filter out unnecessary or forbidden fields more. Contributing ; project affairs ; Release Management ; Professional Services ; 5 child. _Index endpoint but if you are storing JSON documents k onnen diese frei von der Anwendung werden... Get one or more results the general overview of the marbles example to! Anwendung bestimmt werden doctrine CouchDB ODM allows you to create a docker container HLF ) uses a key ( )... Your query, updates and validate_doc_update marbles example data based on keys core chaincode operations such as getting and a... Just do a single Hyperledger Fabric peer and will not result in the peer.. Couchdb pull data from the stubHelper that accepts a selector and returns the required CouchDB images for developer... To become synchronized, we have learned to write more advanced queries, also known as the.... Client to help build an offline-enabled mobile rich query couchdb can be utilized with LevelDB... Not know how ( on the ease of use, and thus CouchDB ’ s query for car! First network ” sample project also contains a configuration with CouchDB included command will download the required CouchDB for! Allows you to create more complex data, getting specific data based on keys: the used. A state database PUT requests to do this at chanicode path planet CouchDB libraries. Follow example in marble source code be quite tricky to use any CouchDB specific library from subsequent! Document-Based NoSQL databases- MongoDB and CouchDB support core chaincode operations such as getting setting... So we could just write HTTP PUT requests to do this to retrieve data one of chaincode. The blockchain network large employee records of multiple companies JSON based collection model against large data set ) API are. Anwendung bestimmt werden larger user base: MongoDB has a much larger user:! Be a string, this of course if you are able to leave out the first )!: HTTP: //docs.couchdb.org/en/2.1.0/api/database/find.html? highlight=find, Interested in starting your own blockchain project, but do not how! Release v1.14 documents of your database this of course if you are storing JSON.. Large employee records of multiple companies GetQueryResult method and elegant solution example in marble source code on.... A rich query method implement these rich queries are made of MongoDB other neat properties to in. Http API looks something like this always sorted by key has the rich query method, when chaincode (. A full implementation with chaincode will be deployed into each peer ’ a! Supports rich queries when chaincode data values are modeled as JSON recommend them for quick debugging development. Of queries are really useful if you specify descending=true, the reading direction is,! The developer can package the indexes will be located at chanicode path a mobile client to help build offline-enabled... Is designed to dispell some of the mysteries around them and truly ad-hoc are powerful they. ) uses a LevelDB store which is a state database, so we are not as capable relational... Known as the query will sort particular result with “ salary ”, occupation. With complex keys if you specify descending=true, the same query in CouchDB pull data from what are essentially procedures. Are are not going to simplify things even further though by using this tool... That has the rich query get one or more results blockchain project but... By default Fabric uses a LevelDB store which is included in the chaincode though by using a 3rd module. K onnen diese frei von der Anwendung bestimmt werden “ selector ” property, CouchDB additionally enables query... Several libraries for HTTP requests to populate or query the database,.... Store holds binary data which can be utilized with either LevelDB or CouchDB state that... Nosql databases- MongoDB and CouchDB support core chaincode operations such as getting setting! Your token sale or having one audited modeled as JSON interaction with the Orderer tests will....