fetch

Fetching data from Oracle to query Table

由 拜拜、爱过 提交于 2019-12-12 01:37:02
问题 I am trying to fetch a query to extract data from an Oracle Database, but get an error message when trying to produce the final data frame to work on. packages already installed library(ROracle) library(RODBC) create the connection to the database con<-dbConnect(Oracle(), username='xxxx', password='xxxx', dbname='xxxx') query the data query<- dbSendQuery(con,"select * from table") execute query and return results in object of type dataframe result<- fetch(query) Everything works fine till the

How to finish Fetch data completely and assign it to component state before proceeding further in componentDidMount React?

由 亡梦爱人 提交于 2019-12-12 01:24:32
问题 I have to perform multiple fetch queries. Based on my first query i have make to make a multiple other queries after receiving all the i should be able to assign the data to the react component state. It appears that i am assigning the values to the component state before the fetch method is finished and hence they appear empty array. I have tried by removing the inner fetch method outside and performing the query. import React, { Component } from 'react'; import './App.css'; import Sensors

Fetch column if row exists using MySQL?

由 冷暖自知 提交于 2019-12-12 01:14:53
问题 I have two tables photo and sale . photo has two columns id and url . sale has two columns photoID and status . The thing is, a photo(row) in photo table doesn't have to have a record in sale table so we do not know if a photo is on sale or not. i.e. photo id | url 1 | http://... 2 | http://... 3 | http://... sale photoID | status 1 | 'sold' 3 | 'pending' As you can see, photo having id 2 doesn't have a record in sale table. What I want to do is to pull all photos from photo table, and if

Caching jsonp callback parameter when doing a backbone fetch

由 戏子无情 提交于 2019-12-11 23:46:32
问题 What is the correct way to cache this callback value when doing a backbone fetch? Have tried overiding the fetch function and setting options.cache = true; but no avail. Ideally we want to continue using fetch, and not write a custom ajax call. The below is an example of the callback parameter that is being appended. I need this to be the same return value each time, i.e so it's acting as a cache. &callback=jQuery1111042059096531011164_1421344480838&_=1421344480840 If more detail is needed

Perl File::Fetch Failed HTTP response: 500 Internal Server Error

由 假如想象 提交于 2019-12-11 21:52:28
问题 I'm using a simple perl script to try and download a file from the following URL: http://www.londonstockexchange.com/products-and-services/trading-services/setsqx/ccp-securities.xls use File::Fetch; my $url = 'http://www.londonstockexchange.com/products-and-services/trading-services/setsqx/ccp-securities.xls'; my $ff = File::Fetch->new(uri => $url); my $file = $ff->fetch() or die $ff->error; I am getting: Fetch failed! HTTP response: 500 Internal Server Error [500 Can't connect to www

In react, how do I pass backend REST APIs to my frontend?

由 我的未来我决定 提交于 2019-12-11 21:30:58
问题 Pretty noobish question here, I do not wish to draw flak. I have my frontend created with create-react-app and I'm using fetch to pass in the backend APIs to my frontend. The backend is running on localhost:8080 on the same machine as the frontend. Frontend is running on port 3000. I have hardcoded the URLs as "http://localhost:8080/getForm" and so on. It all works fine if I access the frontend on the same machine as it is hosted. However, if I access the frontend from a different machine,

Express route /index.js not working in my React app

由 青春壹個敷衍的年華 提交于 2019-12-11 19:57:07
问题 I'm trying to fetch a json object in my React app from index.js in Express, but when it loads I get "Unhandled Rejection (SyntaxError): Unexpected token P in JSON at position 0". I fetched successfully when I used /users.js as the route. (index.js) var express = require('express'); var router = express.Router(); router.get('/', function(req, res, next) { vitamins: [ { name: "Vitamin B2" } ], minerals: [ { name: "Zinc" } ]}); }); (React app) componentDidMount() { fetch('/index') .then(res =>

fetch post is giving me undefined for the posted data?

由 好久不见. 提交于 2019-12-11 18:48:26
问题 Learning how to use Sapper. I have a component with form (the form has one field to enter an email address) and use fetch to post the data to the serverhandle. When I post the data and try to log the data I posted, it logs Undefined. I have no idea why and need help to figure it out. Here is my component with the form and fetch post code: <script> let emailvalue let url = "posthandle" async function handleSubmit(event) { console.log(event); console.log(event.target); emailvalue = event.target

ajax和axios、fetch的区别

由 陌路散爱 提交于 2019-12-11 18:08:02
1.jQuery ajax $.ajax({ type: 'POST', url: url, data: data, dataType: dataType, success: function () {}, error: function () {} }); 传统 Ajax 指的是 XMLHttpRequest（XHR）， 最早出现的发送后端请求技术，隶属于原始js中，核心使用XMLHttpRequest对象，多个请求之间如果有先后关系的话，就会出现 回调地狱 。 JQuery ajax 是对原生XHR的封装，除此以外还增添了对 JSONP 的支持。经过多年的更新维护，真的已经是非常的方便了，优点无需多言；如果是硬要举出几个缺点，那可能只有： 1.本身是针对MVC的编程,不符合现在前端 MVVM 的浪潮 2.基于原生的XHR开发，XHR本身的架构不清晰。 3.JQuery整个项目太大，单纯使用ajax却要引入整个JQuery非常的不合理（采取个性化打包的方案又不能享受CDN服务） 4.不符合关注分离（Separation of Concerns）的原则 5.配置和调用方式非常混乱，而且基于事件的异步模型不友好。 PS:MVVM(Model-View-ViewModel), 源自于经典的 Model–View–Controller（MVC）模式。MVVM 的出现促进了 GUI

ElasticSearch笔记整理（三）：Java API使用与ES中文分词

由 梦想与她 提交于 2019-12-11 17:58:40
[TOC] pom.xml 使用maven工程构建ES Java API的测试项目，其用到的依赖如下： <dependency> <groupId>org.elasticsearch</groupId> <artifactId>elasticsearch</artifactId> <version>2.3.0</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.7.0</version> </dependency> <dependency> <groupId>org.dom4j</groupId> <artifactId>dom4j</artifactId> <version>2.0.0</version> </dependency> <!--使用lombok，对于Java Bean对象，就不用手动添加getter和setter方法，在编译时，它会帮我们自动添加--> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.16.10<
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