Oracle SQL Tips, Tricks and Hacks
Everything Oracle SQL
Menu Close
  • Blog
  • Video Courses
  • Oracle SQL Tutorial

SQL

7

CASE expressions in Oracle SQL

Posted on November 10, 2015 by Carlos

CASE expressions are the standard way to implement IF … THEN … ELSE logic in SQL statements. Oracle provides the DECODE function, which does something similar and is widely used by Oracle developers, but CASE expressions are actually more flexible… Continue Reading →

Basics, SQL CASE, CASE expression, condition, conditional
5

The WITH clause to the rescue!

Posted on October 29, 2015 by Carlos

This time I’m just writing to tell you a story about the WITH clause, because it is really powerful and vastly underutilized. You can read the basics about the WITH clause in my previous article about subqueries. So, this is… Continue Reading →

SQL efficient, Factoring, optimization, Oracle, performance, query, SQL, Subquery, tuning, WITH clause
15

Subqueries in Oracle SQL

Posted on October 1, 2015 by Carlos

Subqueries are a very powerfull feature of SQL, but I have seen them being misused or underused many times, and that is why I decided to write about them today. The Basics For starters, a subquery is a SELECT statement… Continue Reading →

SQL correlated, inline view, non-correlated, scalar, Subquery, subquery factoring, WITH clause
7

Oracle Inner Join Syntax : 4 different ways

Posted on September 4, 2015 by Carlos

I’ve worked with Oracle databases for many years, and during this time I have seen code written by lots of different people. One thing I have noticed is that with few exceptions, people who started working with Oracle many years… Continue Reading →

SQL ANSI, Inner Join, Join, Natural Join, Oracle, SQL, Standard
4

The Powerful DECODE Function

Posted on August 25, 2015 by Carlos

Oracle’s DECODE is one of the functions I find more powerful and one that over the years I have used thousands of times to solve several different kinds of problems. Here I’m going to talk a little bit about how… Continue Reading →

Functions, SQL comparison, count, counting, DECODE, function, greater, less, Oracle, SQL
2

Adding optional conditions to your queries

Posted on August 18, 2015 by Carlos

The NVL function is very useful in a lot of different situations and is probably one of the most widely used among Oracle developers. One of the ways we can use it is to write queries that have ‘optional’ conditions.… Continue Reading →

Functions, SQL condition, NVL, Oracle, query, SQL
7

Oracle NVL, NVL2 and COALESCE functions

Posted on August 13, 2015 by Carlos

I have seen quite a few questions on internet forums and knowledge exchange sites about Oracle NVL, NVL2 and COALESCE functions for handling nulls, so I decided to write an article about them today. Those functions are actually similar, but… Continue Reading →

Functions, SQL COALESCE, function, null, nulls, NVL, NVL2, Oracle, SQL

Post navigation

Newer Articles
Don't want to miss any Oracle SQL tips?

Subscribe to be informed about new posts, tips and more awesome things.

Recent Twitter Activity

Recent Tweets by @CarlosDLG

Recent Posts

  • The SQL Group By Clause
  • The Oracle Multitenant Architecture
  • The FIRST and LAST functions in Oracle SQL
  • Pairwise Comparisons With Subqueries in Oracle SQL
  • How to Change Oracle SQL Developer Language

Categories

  • Basics
  • Functions
  • Oracle Database
  • SQL
  • SQL Developer
  • Tuning

Archives

  • March 2019
  • September 2018
  • April 2018
  • January 2017
  • October 2016
  • August 2016
  • June 2016
  • April 2016
  • January 2016
  • November 2015
  • October 2015
  • September 2015
  • August 2015
© 2021 Oracle SQL Tips, Tricks and Hacks. All rights reserved.
Hiero by aThemes
Shares