q is a command-line utility that allows users to execute SQL queries in tabular format text files (CSV, TSV, and other such formats). Users wanting to accomplish this task without a tool like q would typically need to load the CSV data into database software of some kind. The examples section on the q website provides an analysis of website click-count data and an analysis of file sizes to...

The Structured Query Language (SQL) "is the standard language for relational database management systems." A programmer building an online database will undoubtedly need to be very familiar with SQL, and this site is an excellent starting point. People who have never heard of SQL can learn the basics, or more advanced users can refresh their memories. The essential commands and functions are...