I have a table that looks like this:
id: primary key
content: varchar< br />weight: int What I want to do is to randomly select a row from the table, but consider the weight. For example, if
Tag: How
C # – How to get an instance of BackgroundWorker from the currently executed method?
I’m using a background worker program that can have n instances. The problem is that the DoWork method (with the’sender’ parameter, that is, BackgroundWorker) calls other codes that generate the ca
MySQL – How to SUM Time?
I have a table with date and time values in this format:
Start
1/13/2009 7:00:00 AM
End
1/13/2008 2:57:00 PM
I use the’str to date’ function to convert them Date and
Symfony – How do I handle custom SQL functions in architecture updates?
Sometimes, when you are looking for performance, you need to use some complexity functions and triggers to delegate some responsibilities to the database. I want to know that when you call the doct
Inheritance – How to use a superclass constructor in Qt Creator?
You may know that the classes in Qt Creator are part of the class.h and class.cpp files. Suppose we have two classes A (ah, a.cpp) and B(bh,b.cpp), B inherits A. When using B’s constructor, how t
Inheritance – How to use multiple parent configuration functions with VAL in subclasses
Suppose I have a class Parent, which has four fields A, B, C, and D, so that C and D are optionally passed or initialized using the default implementation:
open class Parent(val a: A, v
Architecture – How does the game status interact with components?
I have been making some modifications to my Flash framework recently. When I make a game every month, the idea of reusing components to quickly build concepts seems very attractive to me.
T
How to share the architecture and configuration between the cores between SOLR 4.4?
I want to migrate from the old solr.xml format to the core automatic discovery in 4.4, but I encountered sharing configuration (solrconfig.xml, schema.xml and related files between cores) ).
Object-oriented JavaScript how to create a static class for constants
I decided to put all the constants in a concise class called constants, and wanted to use the dot operator to access its members.
So far , I have tried:
function Constants(){
Constants
MSBuild – How to retrieve @ (targetoutput) without performing construction
I am implementing an MSBuild framework to drive the construction and deployment of many projects organized as a hierarchical structure.
In order to implement the correct Clean/Clobber logic,