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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...
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 ...
Using Emacs to recursively find and replace in text files not already open
...
M-x find-name-dired: you will be prompted for a root directory and a filename pattern.
Press t to "toggle mark" for all files found.
Press Q for "Query-Replace in Files...": you will be prompted for query/substitution regexps.
Proceed as with query-replace-regexp: SPACE to...
SQLAlchemy: how to filter date field?
..., once it's DateTime or timestamp - it's usually finished with 00:00 (both MySQL & PostgreSQL do this). More generic solution is not to cast, but to set the date you are sending to it's .endOfDay() so you actually send 1988-01-17 23:59:59 to the database compare :)
– jave.w...
How to give ASP.NET access to a private key in a certificate in the certificate store?
...cation.LocalMachine);
serverCert = GetCertificateIfExist("CN=MyROOTCA", StoreName.Root, StoreLocation.LocalMachine);
if (clientCert == null || serverCert == null)
{
var caCert = GenerateCACertificate("CN=MyROOTCA", ref caPrivateKey);
...
Java client certificates over HTTPS/SSL
...te server, using a client certificate.
The server is using an selfsigned root certificate, and requires that a password-protected client certificate is presented. I've added the server root certificate and the client certificate to a default java keystore which I found in /System/Library/Framewor...
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,...
Hibernate Criteria returns children multiple times with FetchType.EAGER
...t the result transformer:
criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
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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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A cron job for rails: best practices?
... How do you call this from the console? I did load "#{Rails.root}/lib/tasks/cron.rake" and rake cron, but got NameError: undefined local variable or method `cron' for main:Object
– B Seven
Jul 22 '11 at 15:40
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