OTN Appreciation Day : Adding Invisible Column

Hi everyone,

First of all, I would like to express my graditude for OTN and Tim Hall who is the father of idea. This is amazing. OTN is a very powerfull community and I am very proud to be part of this community. Thanks for all.

In this article, I’ll give short information about Invisible Columns that has come with the Oracle 12c. I hope this will be a beneficial article in terms of awareness.

With the Oracle 12c, there has been a feature added to tables about the visibility of columns. Now we can easily make the desired columns in the table visible or invisible. In my opinion, this feature was necessary because it seems practical to allow everyone in the tables, which are generically reached, to see every column without creating “view”.

Now, let’s see how an invisible column is created.

CREATE TABLE invColExm
(
colA NUMBER,
colB NUMBER INVISIBLE,
colC VARCHAR2 (100)
);

As can be seen from the example above, after determining the data type the column can be made invisible by inserting the phrase “invisible” to associated column. Now, let’s see in which actions this column is invisible.

1 – SELECT * FROM invColExm; — colB is invisible.

2 – DESC invColExm; — colB column is invisible in the list.

3– /in the table referenced with* ROWTYPE ,
the invisible column cannot be reached,
therefore it’s invisible in here too*/

I think this feature is so useful when you need to hide some important data. Also using and understanding of this feature is so easy.

If you want to learn some detail information about this feature, you can click this link.

Happy OTN Appreciation Day

Emrah METE

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About ... from Emrah METE

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