Technology Errors

WordPress database error Duplicate entry X for key yarpp_content for query UPDATE wp_posts SET, MySQL Error

Today I was adding a note to a WordPress article I had written a couple of days ago and it appeared to POST without issue after I clicked the Update button in the WordPress admin. I went to the front-end of the site to verify the new content formatted correctly and to my surprise it wasn’t displaying so I figured I must have left a HTML tag or something open since I didn’t get any errors within the WordPress admin when I clicked the Update button for the Post. After further review the content didn’t exist and it appeared that the article had not posted the update at all since there were zero revisions from today. Fixing the problem is easy by using the below information that describes where I located the error, the error itself, and how to resolve it by issuing a single MySQL command.

Technology Insights

Find Out What Applications Are Installed From An RPM Package On Linux

Earlier today I was upgrading some packages on a CentOS Linux server and was curious what applications were actually installed with the coreutils RPM package. I knew that this was one of the main RPM packages that had a ton of various applications installed with it however I was not sure specifically which ones. Below are some examples of how to use RPM to find out exactly what is installed with a specific RPM package.

Technology Insights

Use whois To Get More Information About A Domain Name With The Host Switch

Using whois can be a valuable tool to find out more information about a domain via the command line in Linux. A typical whois query can be performed to find out where the domain was purchased and using it again with the -h (host switch) can provide more detailed information about the domain. Using the -h switch will typically provide information such as who purchased the domain, when the domain was purchased, when the domain expires, etc. Below are a couple basic examples of how whois can be used followed by whois queries with the output.