This is cool. I used to prefer PostgreSQL/Postgres over MySQL, but guys at my company preferred MySQL. I’m glad to see Postgres is still around. Here’s a link to the story on ReadWrite.
Sigh, so many broken links, so little time ... when I switched this website to Drupal, I didn't (couldn't) take the time to move all of my static content in the Drupal CMS, so a lot of great content is just sitting out there in static files. To help fix that problem a little bit, here's a link to a collection of Java test project (example projects) that demonstrate all sorts of cool and fun things with Java, including:
Here's a quick post to help anyone that needs a quick JDBC Driver and URL reference when using Postgresql (Postgres) with Java (and JDBC).
The basic Postgresql JDBC Driver and URL information you need is shown here:
Here's a quick demonstration of how to create a Tomcat connection pool (database connection pool) using the Tomcat DBCP library.
I'm not going to go into a detailed explanation here of how Tomcat DBCP works, other than to say that it works for me, and I've tried to include everything here that you'll need to implement your own Tomcat DBCP database connection pool in your web applications.
Java JDBC FAQ: Can you share Java JDBC connection string examples for the most popular relational databases?
Some days we all need something simple, and today I needed the example syntax for a JDBC connection string (the JDBC URL) for MySQL and Postgresql databases. While I was digging through my old examples, I found JDBC connection string examples for other databases, and thought I'd share them all here.
To that end, here are some example Java JDBC connection string examples for various databases, including MySQL, Postgres, SQL Server, and DB2.Back to top
JDBC connection string examples
Here’s a table showing the syntax for JDBC URLs and drivers that I've used on recent projects.
I just ran into a crazy error related to Tomcat and DBCP connection pooling. The error message I got after trying to use the Tomcat DBCP connection pooling in my Java web application was:
For some reason I can never remember how to search for database table fields that are either
NOT NULL. I always try to use the
= operator or something else.
So, for myself, here’s an example of how to perform a SQL query and find all records where a field in a database table is
SELECT * FROM foo WHERE bar IS NULL;
And here’s how to perform a SQL query showing all records in a database table where a column is
If you get a Postgresql error message like this:
ERROR: must be owner of relation [your_table_here]
don't worry too much, it probably means what it says: You don't own the table (or relation) you're trying to modify. Well, I guess you can worry if you can't get someone to fix the permissions, but if you can it's no big deal.
With Postgresql (or Postgres, as I call it) you can execute commands from a file like this:
I just did that to run a subset of the restore commands from a backup file that I created, and it worked just fine. In my case I put the file in my current working directory, but I'll guess that you can also supply a path to the file and it will work from there as well.