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Way to go from recursion to iteration
...RecursiveTraversal(x.c, list);
list.Add(x.key);//finally visit root
}
}
The iterative solution:
int? address = null;
AbcTreeNode x = null;
x = root;
address = A;
stack.Push(x);
stack.Push(null)
while (stack.Count >...
Strings as Primary Keys in SQL Database [closed]
...Good explanation. But holds this true for all SQL databases? I've heard of MySQL performance issues when using random UUID as primary key.
– hgoebl
Aug 27 '17 at 11:08
add a c...
Set default value of an integer column SQLite
...
It's the same logic used in MySQL; the default of a nullable column is already NULL, so to set a default otherwise would imply the column is non-nullable. If you specify a default on a nullable column without declaring it NOT NULL, it may confuse you wh...
Excel to CSV with UTF8 encoding [closed]
...
Needed to export an XLS as CSV to import in MySQL. Using Excel 2003 I exported in format "Unicode Text (.txt)", then used Notepad++ to replace the TAB with ;, then imported the txt-file into phpmyadmin with default "Character set of the file: utf-8", Format "CSV using ...
Dynamically change color to lighter or darker by percentage CSS (Javascript)
...format, then use calc() to manipulate them.
Here's a basic example:
:root {
--link-color-h: 211;
--link-color-s: 100%;
--link-color-l: 50%;
--link-color-hsl: var(--link-color-h), var(--link-color-s), var(--link-color-l);
--link-color: hsl(var(--link-color-hsl));
--link-colo...
Unzip a file with php
...he destination to extract to or remove -d yourDestinationDir to extract to root dir.
$master = 'someDir/zipFileName';
$data = system('unzip -d yourDestinationDir '.$master.'.zip');
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Why should I use document based database instead of relational database?
... my schema, I am constantly frustrated by having to maintain the schema in MySQL/SQLite. While I've not done too much with CouchDB yet, I do like how simple it is to evolve the schema during the RAD process.
A case where you might not want to use a non-relational database is when you have a lot of ...
What is a classpath and how do I set it?
...ut.vm anywhere in "no package". This can be a JAR, regular folder, ... The root of any of the locations in the application's classpath.
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What is the aspnet_client folder for under the IIS structure?
...ms that the 'prototype' for the contents of the folder is in C:\inetpub\wwwroot\, and it seems reasonable to suppose that if any given IIS website lacks a /aspnet_client resource, then IIS will try to do the right thing and ... as a last resort ... make a physical folder in the web site root folder,...
Computed / calculated / virtual / derived columns in PostgreSQL
...s defined in the SQL standard and implemented by some RDBMS including DB2, MySQL and Oracle. Nor the similar "computed columns" of SQL Server.
STORED generated columns are introduced with Postgres 12. Trivial example:
CREATE TABLE tbl (
int1 int
, int2 int
, product bigint GENERATED ALWAYS...