Oracle Not Equals Operator

Question

There are two not equals operator - != and <>.

What\'s the difference between them? I heard that != is more efficient than

Answer 1

The difference is :

"If you use !=, it returns sub-second. If you use <>, it takes 7 seconds to return. Both return the right answer."

Oracle not equals (!=) SQL operator

Regards

Answer 2

As everybody else has said, there is no difference. (As a sanity check I did some tests, but it was a waste of time, of course they work the same.)

But there are actually FOUR types of inequality operators: !=, ^=, <>, and ¬=. See this page in the Oracle SQL reference. On the website the fourth operator shows up as ÿ= but in the PDF it shows as ¬=. According to the documentation some of them are unavailable on some platforms. Which really means that ¬= almost never works.

Just out of curiosity, I'd really like to know what environment ¬= works on.

Answer 3

There is no functional or performance difference between the two. Use whichever syntax appeals to you.

It's just like the use of AS and IS when declaring a function or procedure. They are completely interchangeable.

Answer 4

They are the same, but i've heard people say that Developers use != while BA's use <>

Answer 5

They are the same (as is the third form, ^=).

Note, though, that they are still considered different from the point of view of the parser, that is a stored outline defined for a != won't match <> or ^=.

This is unlike PostgreSQL where the parser treats != and <> yet on parsing stage, so you cannot overload != and <> to be different operators.

Answer 6

Developers using a mybatis-like framework will prefer != over <>. Reason being the <> will need to be wrapped in CDATA as it could be interpreted as xml syntax. Easier on the eyes too.