MySQL cheat sheet
MySQL cheat sheet The SQL cheat sheet provides you with the most commonly used SQL statements for your reference. Getting started Connect MySQL mysql -u <user> -p mysql [db_name] mysql -h…Read more →
Articles Written By: Michael Zhang
PostgreSQL cheat sheet
PostgreSQL cheat sheet The PostgreSQL cheat sheet provides you with the common PostgreSQL commands and statements. Getting started Getting started Switch and connect $ sudo -u postgres psql List all databases postgres=# \l…Read more →
How to fix error “Failed to download metadata for repo AppStream… in CentOS”?
How to fix error "Failed to download metadata for repo AppStream... in CentOS"? When you run yum update, you may see error said "Failed to download metadata for repo AppStream...",…Read more →
How to install bootstrap 5 and make it work with Ruby 2.7.2 + on Rails 6.1 +
Rails 6 follow webpacker, you don't need to install a gem, do this instead In your Rails home directory, run this command, to install jQuery, popper.js and bootstrap, jQuery and…Read more →
How to upgrade Node.js from v10.19.0 to v12.13.0 in Ubuntu 20?
Key words: Ruby on Rails,node.js, webpack and stimulus,Ubuntu 20 problem to solve: error tailwindcss@2.2.19: The engine "node" is incompatible with this module. Expected version ">=12.13.0". Got "10.19.0" how to fix?…Read more →
How to Visual Studio Coder debug get rid of loading previous DLLs
key words: Visual Studio Coder Debug Executing task: C:\Program Files\dotnet\dotnet.exe build D:\study\Ex_Files_Debugging_C_Sharp/Ch1/01_03/end/01_03.csproj /property:GenerateFullPaths=true /consoleloggerparameters:NoSummary < Microsoft (R) Build Engine version 16.10.0+4242f381a for .NETCopyright (C) Microsoft Corporation. All rights reserved. MSBUILD…Read more →
How to resolve an IndexOutOfRangeException?
I have some code and when it executes, it throws a IndexOutOfRangeException, saying, Index was outside the bounds of the array. What does this mean, and what can I do…Read more →
BC30451 ‘__o’ is not declared :The name ‘__o’ does not exist in the current context
SeverityCodeDescriptionProjectFileLineSuppression StateErrorBC30451'__o' is not declared. It may be inaccessible due to its protection level.ProjectC:\inetpub\wwwroot\XYZ\ClientMasterPage.master87Active I found out that if I choose Build Only instead of Build + IntelliSense the errors…Read more →
How to comment a line? Too many different to remember?
How to comment out a line in Visual Studio? Differrent language uses different method to comment out a line. .aspx file: <% -- --%> .vb file: apostrophy ' line…Read more →
How to install SSDT in VS (Visual studio) 2019 or 2017
Most Visual studio users are using VS 2017 or 2019 now. To those who are focusing on developing SSIS ETL packages, SSDT is a must tool to have. So how…Read more →