SQL Data Types
SQL Data Types Overview In SQL, as in many other programming languages, every piece of data has a particular type. For example, 11 is an integer, and GǣWall StreetGǥ is a text string. The SQL standar...
Database
SQL Perl/PL Overview
Procedural languages provide the fundamental method for programming within an SQL database. In other articles in this series, we have covered the SQL-based procedural languages, but those are general...
SQL Functions
SQL Programming Overview In the article SQL Programming, we discussed creating the “Hello, World!” function in PostgreSQL, MySQL, and Oracle. In this article, we take “Hello, World!...
SQL Programming
SQL Programming Overview Anybody who has done something for a long time has probably wanted to change how things work at some point or another. A worker at a mill might have found a more efficient wa...
Distributed Databases
Distributed Databases Overview Suppose you created a database for a web application a few years ago. It started with a handful of users but steadily grew, and now its growth is far outpacing the serv...
Database Concurrency and Reliability
Concurrency and Reliability Overview Concurrency and reliability have long been Gǣhot topicsGǥ of discussion among developers and users of distributed systems. The fundamental problem can be seen in ...
Relational Databases
What is a Relational Database? Popular, modern databases are built on top of an idea called Gǣrelational algebraGǥ, which defines how GǣrelationsGǥ (e.g. tables and sequences in databases) interact w...
SQL Keys
SQL Keys Overview In SQL, keys are used to maintain referential integrity among relations. Put simply, this means keys allow tables to reference each other, and each reference will be GǣcorrectGǥ eve...
SQL Table Commands
SQL Table Commands Overview As mentioned previously in this series of SQL articles, databases are primarily composed of tables. The Gǣcolumns and rowsGǥ structure of the table allows data to be effic...
SQL Overview
SQL Overview The SELECT command in SQL provides a robust means for retrieving data from a database. More specifically, SELECT returns a result set of zero or more rows from the database, and this res...