eval

Flink 1.9 实时计算 - SQL 维表 Join 的实现

由 天大地大妈咪最大 提交于 2020-01-02 14:51:18
前言 Flink 1.9 版本可以说是一个具有里程碑意义的版本，其内部合入了很多 Blink Table/SQL 方面的功能，同时也开始增强 Flink 在批处理方面的能力，真的是向批流统一的终极方向开始前进。Flink 1.9 版本在 8.22 号也终于发布了。本文主要介绍学习 Flink SQL 维表 Join，维表 Join 对于SQL 任务来说，一般是一个很正常的功能，本文给出代码层面的实现，和大家分享用户如何自定义 Flink 维表。 1. 什么是维表 维表作为 SQL 任务中一种常见表的类型，其本质就是关联表数据的额外数据属性，通常在 Join 语句中进行使用。比如源数据有人的身份证号，人名，你现在想要得到人的家庭地址，那么可以通过身份证号去关联人的身份证信息，就可以得到更全的数据。 维表可以是静态的数据，也可以是动态的数据(比如定时更新的数据)，一般会通过特定的主键来进行关联。它可以在 Mysql 中进行存储，也可以在 Nosql 数据库中进行存储，比如 HBase等。 2. Flink 中的维表 Flink 1.9 中维表功能来源于新加入的Blink中的功能，如果你要使用该功能，那就需要自己引入 Blink 的 Planner，而不是引用社区的 Planner。由于新合入的 Blink 相关功能，使得 Flink 1.9 实现维表功能很简单，只要自定义实现

Allowing the repr() of my class's instances to be parsed by eval()

由 こ雲淡風輕ζ 提交于 2020-01-02 09:27:35
问题 Say I have defined a class myself and I defined a __repr__ method for it. I want to about convert it back to my object. I know that object serialization may be a good way of doing so (using the json module) but is there anyway I can use the built-in eval function to achieve this? 回答1: Write your __repr__() so it creates a valid Python expression for instantiating your object. class MyClass(object): def __init__(self, a, b): self.a = a self.b = b def __repr__(self): return "%s(%r, %r)" % (type

(SyntaxError): missing ] after element list when using eval

由 被刻印的时光 ゝ 提交于 2020-01-02 09:19:06
问题 I get following error (SyntaxError): missing ] after element list when using eval function. Returned JSON is pretty simple, so I don't undestand where is error. [{"title":"sfsdf","id":1}{"title":"m356","id":12}] 回答1: As an answer for completeness. Your JSON is invalid. You need a comma between the Objects like so: [{"title":"sfsdf","id":1},{"title":"m356","id":12}] 回答2: First you have lost the comma between the Object,the Second Jquery will parse the Object automaticly. i suggest you don't

Convert flattened key->value pairs to a nested object

由 孤者浪人 提交于 2020-01-02 07:13:33
问题 What would be the easiest way to convert the following key->value object "array" to a proper "JSON" style object? Example below would be converting input into graph. var input = { "graph.default.seriesColor" : ["#cccccc", "#3c3c3c"], "graph.default.stackSeries" : false, "graph.default.title.text" : "Hello!", "graph.default.title.show" : false, "graph.default.axesDefaults.show" : true, "graph.default.axesDefaults.min" : 17, "graph.default.axesDefaults.max" : 20, }; var graph = { default: {

Javascript difference between eval() and appending script tags

由 守給你的承諾、 提交于 2020-01-02 02:28:10
问题 I was wondering if someone could explain the difference between using Javascript's eval(), and another approach, like using JQuery to create script tags and then appending that element to the page: eval(somecode); vs. $("<script type='text/javascript'>"+somecode+"</script>").appendTo("head"); Not sure if this is relevant, but here's the context: I'm working with a version of the Drupal Popups module whose basic purpose is to easily turn regular links into popups by AJAX'ing an entire page

Use of eval in Python, MATLAB, etc [duplicate]

由 这一生的挚爱 提交于 2020-01-02 02:04:11
问题 This question already has answers here : Why is using 'eval' a bad practice? (8 answers) Closed 6 years ago . I do know that one shouldn't use eval . For all the obvious reasons (performance, maintainability, etc.). My question is more on the side – is there a legitimate use for it? Where one should use it rather than implement the code in another way. Since it is implemented in several languages and can lead to bad programming style, I assume there is a reason why it's still available. 回答1:

dynamically create a class without a namespace

由 ∥☆過路亽．° 提交于 2020-01-01 07:11:25
问题 I am trying to dynamically create a class using the eval method. It is working fine except for one small problem. As my code shows I am creating the Browser class inside the BrowserFactory class. When I do this the Browser class has an added namespace of BrowserFactory. Is there anyway to evaluate the Browser class from a string without the BrowserFactory namespace being attached? class BrowserFactory def self.create_browser(browser) super_class = nil case browser when 'IE' require 'watir'

how to convert string to code in c# [closed]

由 不问归期 提交于 2020-01-01 04:01:11
问题 As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 7 years ago . I saw there is such question in c++ I am a very begginer and I need a very simple example how to do it . the user writes code in the

how to bind javascript function with OnClientClick event with Eval?

由 南笙酒味 提交于 2020-01-01 02:53:10
问题 my link button - <asp:LinkButton runat="server" ID="lbtnEdit" Text="edit" OnClientClick="javascript:msgDisp('<%# Eval(LocationId).toString() %>')" /> and the javascript msgDisp is- <script type="text/javascript" language="javascript"> function msgDisp(lid) { alert(lid); } </script> but it is not giiving LocationId in pop but the whole string <%#......%> is comin in popup message. How can I pass Eval values in javascript. 回答1: You can build the entire contents of OnClientClick as a string

is there a way to execute a function when I have its name in a string [duplicate]

由 北慕城南 提交于 2019-12-31 05:59:11
问题 This question already has answers here : How to execute a JavaScript function when I have its name as a string (33 answers) Closed 5 years ago . Consider I have a name of a function which does not require any argument in a var - var fn = "foo"; Can I execute it in some or similar like this - eval(fn); It does not work. Please suggest. My definition of function will look like this - function foo() { ....do something.... } 回答1: try this eval(fn)(); or this eval(fn + "()"); 回答2: Please do not
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