I fielded a question from blog reader on a three year old post about the EOMONTH (End Of Month) function in Excel. The reader want to write a mega-function (a term for putting two or more functions together to solve a problem, according to Mr. Excel). The function would return the first day of any month for the first day of the month and the first day of the next month for any day (more...)
How time flies, last March I explained how to install and configure PostgreSQL on Windows. It was my intent to start posting more content on PostgreSQL but I was distracted by another writing commitment on Oracle Database 12c PL/SQL Advanced Programming Techniques, which should be available in November. It tempted me away from PostgreSQL because I got to write about how to use Java inside Oracle Database 12c, which was fun. Having (more...)
The ability to deploy Java inside the Oracle database led somebody to conclude that the source isn’t visible in the data catalog. Then, that person found that they were wrong because the Java source is visible when you use a DDL command to
COMPILE the Java source. This post discloses how to find the Java source and how to prevent it from being stored in the data catalog.
For example, (more...)
Some of my students want to learn to write C++ on a Windows OS. At some point, you simply surrender to the fact that many people prefer the Windows OS as a starting point. Traditionally, I’d recommend the Microsoft Visual Studio as their learning vehicle because it’s free to our students because of our relationship with Microsoft. It’s not free to graduates. When a graduate contacts me I recommend Code::Blocks. Just recently, one ask for (more...)
New update of VMWare came out, and it is time to upgrade VMWare Tools. Here’s an update on the instructions for upgrading VMWare Tools:
- Navigate to the VMWare Menu, choose Virtual Machine and in the drop down menu Install VMWare Tools. This will mount a virtual CD in the Oracle Unbreakable Linux virtual machine and it launches the following dialog box:
- Open a terminal session by right clicking anywhere in the desktop, and then choose (more...)
I left to chance where students would attempt to place their external files in a Linux or Unix implementation. As frequently occurs, they choose a location in their
student user’s home directory. Any attempt to read an external table based on a file in this type of directory fails because it’s not accessible by the Oracle user. You can’t simply
chown the directory and files in the directory.
The failure returns the following result:
A call to a
PRICE_S1 sequence in a query with an
ORDER BY clause is disallowed. Any attempt raises the following exception:
SELECT price_s1.NEXTVAL AS price_id * ERROR at line 1: ORA-02287: SEQUENCE NUMBER NOT allowed here
You need to remove the
ORDER BY clause to eliminate the error.
While working with an error that my students surfaced in the Oracle Database 12c, I blogged about the limit of using a subquery in an Oracle
INSERT statement, and I discovered something when retesting it in MySQL. It was a different limitation. I was also surprised when I didn’t find any mention of it through a Google search, but then I may just not have the right keywords.
The original test case (more...)
Sometimes my students find new errors that I’ve never seen. One student did that this week by including an
ORDER BY clause in a subquery that feeds an
INSERT statement. It raises an
ORA-00907 exception, like:
ORA-00907: missing right parenthesis
You can’t include a subquery with an
ORDER BY clause because it generates an error. The reason is simple. A subquery can’t perform a sort operation inside a subquery. Here’s a quick (more...)
It’s seldom that Oracle makes an effort to give an Oracle Press book away for free, but they’ve done it. You can download the Getting Started with Oracle NoSQL Database book from Oracle Press for free.
Getting Started with Oracle NoSQL Database
- Overview of Oracle NoSQL Database and Big Data
- Introducing Oracle NoSQL Database
- Oracle NoSQL Database Architecture
- Oracle NoSQL Database Installation and Configuration
- Getting Started with Oracle NoSQL Database Development
- Reading and Writing Data