Tag:data source

  • The technical function tells you in a short and smooth way: the extended implementation of Flink SQL

    Time:2020-2-22

    On January 28, 2019, Alibaba cloud announced that blink, the open-source “computing ace” real-time computing platform, will give back to the Apache Flink community. According to the official, the computing delay has been reduced to millisecond level, that is to say, you blink when browsing the web, and the information processed by Taobao and tmall […]

  • Uipickerview basic use

    Time:2020-2-22

    Uipickerview is a very common UI control, which is necessary for various shopping platforms to select addresses. Let’s talk about the specific use First, uipickerview is created. Like most controls, it allocates memory and sets the location size. It is important to set up the agent and data source and obey the agent and data […]

  • C ා general query

    Time:2020-2-20

    Many general-purpose queries do not support and and or in query criteria very well, either all are and or all are or. After a period of exploration, the author has finally completed a relatively satisfactory general query, Multi conditional and and or can be realized. Now, the implementation process is recorded as follows: 1. Add […]

  • High concurrency

    Time:2020-2-17

    Server performance, database performance, network connection and even programming language all affect the concurrency. But in summary, high concurrency is nothing more thanSplit split split。 Optimistic lock Optimistic lock is a model of database optimization. That is, by “version control” of data entries, data can be constrained to prevent dirty read-write operations. Resources are not […]

  • WinForm delete dataGridView reported exception: System.IndexOutOfRangeException: “index 7 has no value

    Time:2020-2-17

    The WinForm interface is as follows: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; namespace form1 { public partial class Form1 : Form { List data = GetStudents(); public Form1() { InitializeComponent(); this.dataGridView1.DataSource = data; } public static List GetStudents() { return new List() { […]

  • Loading feature master data to automatically delete duplicate key values

    Time:2020-2-17

    When extracting the attribute data of information object, an error is found. After checking, it is found that the data source has duplicate key values Originally, I wanted to delete duplicates in the start routine and found that DTP already has this function. Check [process duplicate key value] in DTP [update] After re execution, duplicate […]

  • Using FastReport report report tool to realize envelope envelope printing function

    Time:2020-2-15

    In the earlier report template printing, I tend to use lodop ActiveX for report printing or template printing, and the BS effect is very good. Before, we used it to implement envelope printing function in WinForm program. For details, please refer to the implementation process of envelope printing and batch printing. Although the function can […]

  • Spring boot multi data source redis configuration

    Time:2020-2-13

    Summary Based on spring boot 2.0.7, this paper explains how to configure redis with multiple data sources. Lettuce is used as the redis client, and an example code is attached. Redis configuration configuration file skyarthur: redis1: host: 127.0.0.1 port: 6378 lettuce: pool: min-idle: 5 max-idle: 10 max-active: 8 max-wait: 1ms shutdown-timeout: 100ms redis2: host: 127.0.0.1 […]

  • Ctrip’s real-time feature platform based on Flink

    Time:2020-2-12

    Author: Liu Kang This paper is from the Flink meetup meeting held in Shanghai on July 26, sharing with Liu Kang. At present, I am engaged in the development of model life cycle related platforms in the big data platform department, and now I am mainly responsible for the development of real-time model feature computing […]

  • Quick integration of SSM framework, case demonstration

    Time:2020-2-11

    Before you watch this article, at least make sure you have some knowledge of Spring + spring MVC + mybatis and are familiar with using Maven for project construction. New Maven web project Here I only list the general directory structure. Please change it according to your own requirements. Framework integration 1.To writepom.xmlAdd dependency required […]

  • It is simpler to subscribe to mongodb data changes than to parse MySQL binlog

    Time:2020-2-9

    Preface We have opened a project of subscribing and distributing MySQL binlog, which has been used very well all the time. Suddenly one day, we asked whether we could support mongodb’s data subscription. Mongodb is also widely used. Arrangements. After a simple understanding, it was found that mongodb has a similar binlog mechanism. It took […]

  • . net core simple timer

    Time:2020-2-7

    using Microsoft.Extensions.Configuration; using Microsoft.Extensions.Hosting; using Orleans; using Star.Helpers; using Star.IModuleServices.Common.Interfaces.System; using Star.IModuleServices.Common.Models.System.SettingHotUpdate.Responses; using System; using System.Collections.Concurrent; using System.Collections.Generic; using System.Threading; using System.Threading.Tasks; using Star.Service.Project.Admin.Tool.ConfigTime; namespace Star.Service.Project.Admin.Tool.ConfigTime { /// ///Simple scheduled task execution /// public class TimedExecutService : BackgroundService { protected override async Task ExecuteAsync(CancellationToken stoppingToken) { try { Console. Writeline (datetime. Now. Tostring() + “backgroundservice: […]