Complete IT Professional

Are you getting the “ORA-01031 insufficient privileges” error? Learn what causes this error and how to resolve it in this article. ORA-01031 Cause The cause of the ORA-01031 error is that you’re trying to run a program or function and you don’t have the privileges to run it. This could happen in many situations, such […]

Have you received an ORA-00937: not a single-group group function error? Learn what it is and how to fix it in this article. ORA-00937 Cause The cause of the ORA-00937 error is that a SELECT statement is trying to be executed, and the SELECT statement has an aggregate function (e.g. COUNT, MIN, MAX, SUM, or […]

Are you going for a job where you need to know SQL, such as a Database Developer or Database Administrator? Brush up on your interview questions with this extensive list of SQL interview questions. This collection of interview questions on SQL has been collated from my experience with SQL and from various websites. It contains […]

Did you get an ORA-00907: missing right parenthesis error? Learn what caused it and how to resolve it in this article. ORA-00907 Cause When working with Oracle SQL, all left parenthesis (the “(” character) must be paired with a right parenthesis character (the “)” character). If there are more left parentheses than right parentheses, then […]

Are you getting an ORA-06502 error message when working with Oracle SQL? Learn how to resolve it and what causes it in this article. ORA-06502 Cause The cause of the “ORA-06502 PL/SQL numeric or value error” can be one of many things: A value is being assigned to a numeric variable, but the value is […]

The Oracle GROUP BY clause is a powerful clause, especially when analysing large amounts of data. Learn what the GROUP BY clause is and everything you can do with it in this article. In this article, we will cover: What Is The GROUP BY Clause? Sample Data Examples of Aggregate Functions with GROUP BY Filtering […]

Are you getting the ORA-06550 error when running an SQL statement? Learn the cause of this error and the solution in this article. Demonstration of the Error To demonstrate this error, I can run this code: CREATE OR REPLACE PROCEDURE testProcedure AS   textValue VARCHAR2(3); BEGIN   textValue := someOtherValue; END; If I compile this […]

Are you getting the ORA-00933: SQL command not properly ended error? Learn what causes it and how to resolve it in this article. ORA-00933 Cause You have run an SQL statement and have gotten this error: ORA-00933: SQL command not properly ended What causes this error? Most likely, the SQL statement you’re running has a […]

The Database Star Academy membership is now open! Here’s what you need to know. What Is the Database Star Academy Membership? It’s a membership site with a monthly fee, that gives you access to many different online video courses and PDF guides related to Oracle database development. What’s Included? As part of your membership, you […]

In this article, I’ll explain what I mean by “focused learning” and why it’s a good idea for your career. What is Focused Learning? When we want to learn something, we tend to research on it. We look for websites, articles, videos on the topic. Or we enrol in a university course, if it’s career […]

The Database Star Academy membership will be launching very soon. Read on to find out more. What Is The Database Star Academy Membership? Over the last couple of years, I’ve developed several video courses and PDF guides to help database developers improve their SQL skills and their career. Up until now, I’ve made these available […]

Here’s a collection of interesting articles I’ve read this week. Articles I’ve Read Truncate 12c https://jonathanlewis.wordpress.com/2017/02/16/truncate-12c/ Jonathan Lewis writes an article about some improvements to the TRUNCATE statement in Oracle 12c, and how it relates to “on delete cascade”. THere’s a small example and a good explanation on how it works.   Step by Step […]

Did you get an ORA-00936: missing expression error? Learn what it means and how to resolve it in this article. ORA-00936 Cause The error you’ve gotten is this: ORA_00936: missing expression Oracle’s official “cause and action” that appears along with the error is: Cause: A required part of a clause or expression has been omitted. […]

What’s the difference between UNION and UNION ALL in Oracle SQL? There are a few. Learn what they are in this article. What Is UNION and UNION ALL? First of all, let’s explain what they are. UNION and UNION ALL are both “set operators”. They are keywords you can use to combine two sets of […]

Here’s a collection of interesting articles I’ve read this week Articles I’ve Read DBA Productivity and Oracle Database 12.2 https://juliandontcheff.wordpress.com/2017/02/09/dba-productivity-and-oracle-database-12-2/ Julian writes about automating the tasks a DBA does, and shows a chart demonstrating which tasks are performed manually vs automated. He also covers some of the new automation features for DBAs in releace 12cR2. […]

Are you getting an “ORA-00911 invalid character” error when running an SQL statement? Find out what causes it and how to resolve it in this article. ORA-00911 Cause So, you’ve tried to run an SQL statement, such as INSERT or SELECT, and gotten this error: ORA-00911: invalid character Why did this happen? According to the […]

Did you get an ORA-06512 error when running an SQL query? Learn what this error is and how to resolve it in this article. ORA-06512 Cause The error message you get will look similar to this: ORA-06512: at line n. Where n is a line number. This error message is a generic PL/SQL error message […]

Oracle has several character data types that are commonly used and can also be confusing if you don’t know the differences between them. Learn what they are and the differences between them in this article. The Oracle character data types that are used most often are CHAR and VARCHAR2. There is also a VARCHAR data […]

Here’s a collection of articles I’ve read over the last week that I found interesting. A shorter list than usual, but still some quality articles! Articles I’ve Read Oracle’s Cloud Licensing Change : Be Warned! https://oracle-base.com/blog/2017/01/28/oracles-cloud-licensing-change-be-warned/ Tim Hall from Oracle-Base shared with the community that Oracle’s cloud licensing costs have doubled due to the way […]

Have you gotten an “ORA-01722 invalid number” error? I’ll explain what this error is and how you can resolve it in this article. ORA-01722 Cause So, you’ve run an SQL query (which can be SELECT, INSERT, UPDATE, for example), and you’ve gotten this error: ORA-01722: invalid number The reason for this error is that Oracle […]