用UUID从NodeJS查询Cassandra

Question

谢谢你抽出时间来看我的问题。我和我的团队刚刚开始研究NodeJS，这是我们第一次遇到一个到目前为止我们还无法找到解决方案的问题。

简单地说，我们有一个Controller，它需要用一个UUID主键查询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"
};

DB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密钥空间模式：

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行中，我不知道如何获得checklistId (它是URL中的UUID )来正确地查询Cassandra表。我想，我必须对checklistId做一些事情，然后才能使用它与卡桑德拉中这个表的id列中的内容进行比较。

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' }

任何帮助都将不胜感激！

Answer 1

应该查询Uuid类型，不要使用引号(")。

我不是NodeJS专家，但也许你应该使用卡桑德拉类型的uuid？

有关于uuid的Datastax文章：

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

Answer 2

@nevsv --你是对的我觉得这应该是特快卡桑德拉文件的一部分，但很高兴我找到了答案。

为了帮助其他人，在模型中需要这样做：

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

希望这能帮到别人！

Answer 3

今天，我在使用Casandra编写一个Express应用程序时遇到了这个问题。解决方案是使用在模型对象中定义的方法uuidFromString。您可以在这里找到更多信息：https://express-cassandra.readthedocs.io/en/stable/datatypes/