用NodeJS的UUID查询Cassandra

感谢您花时间看我的问题。 我和我的团队刚刚开始涉足NodeJS，这是我们第一次遇到一个问题，至今我们还找不到解决scheme。

简而言之，我们有一个Controller，需要用一个UUID主键来查询Cassandra。

控制器：

'use strict'; const express = require('express'); const models = require('../dbConnection'); const router = express.Router(); var UUID = require('uuid-js'); // Store / create checklist definition. router.post('/', function(req, res) { }); // Show checklist definition. router.get('/:id', function(req, res) { let checklistId = req.params.id; console.log(checklistId); models.instance.ChecklistDefinition.findOne({id: checklistId}, function(err, checklist) { if (err) { console.log(err); return; } res.json(checklist); }); }); // Update checklist definition. router.put('/:id', function(req, res) { }); // Delete checklist definition. router.delete('/:id', function(req, res) { }); module.exports = router; 

模型：

 module.exports = { fields: { id : "uuid", client_id : "int", name : "text" }, key : ["id"], indexes: ["name"], table_name: "checklist_definition" }; 

数据库连接：

 const models = require('express-cassandra'); //Tell express-cassandra to use the models-directory, and //use bind() to load the models using cassandra configurations. models.setDirectory( __dirname + '/models').bind( { clientOptions: { contactPoints: ['127.0.0.1'], protocolOptions: { port: 9042 }, keyspace: 'audit_checklist', queryOptions: {consistency: models.consistencies.one} }, ormOptions: { //If your keyspace doesn't exist it will be created automatically //using the default replication strategy provided here. defaultReplicationStrategy : { class: 'SimpleStrategy', replication_factor: 1 }, createKeyspace: true } }, function(err) { if(err) console.log(err.message); else console.log(models.timeuuid()); } ); module.exports = models; 

Cassandra Keyspace模式：

 CREATE KEYSPACE audit_checklist WITH durable_writes = true AND replication = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 }; CREATE TABLE audit_checklist.checklist_definition ( id uuid, client_id int, name text, PRIMARY KEY (id) ) WITH bloom_filter_fp_chance = 0.01 AND comment = '' AND crc_check_chance = 1.0 AND dclocal_read_repair_chance = 0.1 AND default_time_to_live = 0 AND gc_grace_seconds = 864000 AND max_index_interval = 2048 AND memtable_flush_period_in_ms = 0 AND min_index_interval = 128 AND read_repair_chance = 0.0 AND speculative_retry = '99.0PERCENTILE' AND caching = { 'keys' : 'ALL', 'rows_per_partition' : 'NONE' } AND compression = { 'chunk_length_in_kb' : 64, 'class' : 'LZ4Compressor', 'enabled' : true } AND compaction = { 'class' : 'SizeTieredCompactionStrategy', 'max_threshold' : 32, 'min_threshold' : 4 }; CREATE INDEX checklist_definition_name_index ON audit_checklist.checklist_definition (name); 

在models.instance.ChecklistDefinition.findOne这一行，我无法弄清楚如何获得checklistId （这是URL中的一个UUID），以正确查询Cassandra表。 我可以想象，我必须在checklistId之前做一些事情，然后才能使用它来与Cassandra中该表的id列进行比较。

我得到的错误是：

 apollo.model.validator.invalidvalue: Invalid Value: "6c84fb90-12c4-11e1-840d-7b25c5ee775a" for Field: id (Type: uuid) at f (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express-cassandra/lib/orm/apollo_error.js:174:15) at Function.f [as _get_db_value_expression] (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express-cassandra/lib/orm/base_model.js:999:11) at /Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express-cassandra/lib/orm/base_model.js:1144:34 at Array.forEach (native) at Function.f [as _create_where_clause] (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express-cassandra/lib/orm/base_model.js:1018:28) at Function.f [as _create_find_query] (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express-cassandra/lib/orm/base_model.js:1196:26) at Function.f [as find] (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express-cassandra/lib/orm/base_model.js:1482:26) at Function.f [as findOne] (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express-cassandra/lib/orm/base_model.js:1541:15) at /Users/shanejeffery/Desktop/compli-docker/audit-checklist/controllers/ChecklistDefinitionController.js:21:41 at Layer.handle [as handle_request] (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express/lib/router/layer.js:95:5) at next (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express/lib/router/route.js:131:13) at Route.dispatch (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express/lib/router/route.js:112:3) at Layer.handle [as handle_request] (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express/lib/router/layer.js:95:5) at /Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express/lib/router/index.js:277:22 at param (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express/lib/router/index.js:349:14) at param (/Users/shanejeffery/Desktop/compli-docker/audit-checklist/node_modules/express/lib/router/index.js:365:14) name: 'apollo.model.validator.invalidvalue' } 

任何帮助将不胜感激！

Answer 1

应该查询Uuidtypes而不用引号（“）。

我不是一个NodeJS专家，但也许你应该使用cassandratypesuuid？

有关于uuid的Datastax文章：

http://docs.datastax.com/en/developer/nodejs-driver/latest/features/datatypes/uuids/

Answer 2

@nevsv – 你完全正确。 我觉得这应该是express-cassandra的文档的一部分，但很高兴我明白了这一点。

为了帮助他人，这是模型中需要发生的事情：

 module.exports = { fields: { id : { type: "uuid", default: {"$db_function": "uuid()"} }, client_id : "int", name : "text" }, key : ["id"], indexes: ["name"], table_name: "checklist_definition" }; 

希望能帮助别人！