What is the difference between <> and != operators in MySQL?

Question

If I use a simple table such as :

create table test ( a int );
insert into test values ( 1 ) , ( 2 ) , ( 2 ) , ( 3 );
select * from test where a <> 2;
select * from test where a != 2;

Both give me :

+------+
| a    |
+------+
|    1 |
|    3 |
+------+
2 rows in set (0.00 sec)

So what is the difference between <> and != mysql operators ?

I can't find any documentation explicitly saying so, but they are synonymous. — vcsjones, Jan 04 '13 at 15:03

score 32 · Answer 1 · answered Jan 04 '13 at 15:10

32

<> should be preferred, all things being equal, since it accords with the sql standard and is technically more portable...

!= is non-standard, but most db's implement it.

sql:2008 grammar:

<not equals operator> ::=
  <>

answered Jan 04 '13 at 15:10

echo_Me

2

why is it technically more portable? – Dennis Jun 19 '17 at 20:29
1

@Dennis I guess because it is sql standard. – Cave Johnson Jun 14 '18 at 20:11
1

@Dennis it should be more compatible to use `<>` and easily to transplant the query in different RDBMS. so it's considering portable? – mingchau May 05 '19 at 03:35

score 30 · Accepted Answer · answered Jan 04 '13 at 15:03

30

They are both exactly the same. See the documentation.

answered Jan 04 '13 at 15:03

anothershrubery

1

Thank you, strange notation. Just seen that on a coworker code and just got stuck. – Alain Tiemblo Jan 04 '13 at 15:06
1

Yeah, while I use C-based languages mainly I tend to use `<>` even though `!=` feels more natural to me. `<>` just seems right for any SQL representation. – anothershrubery Jan 04 '13 at 15:07

score 7 · Answer 3 · answered Jan 04 '13 at 15:04

7

No difference. <> is sql standard, != non-standard.

answered Jan 04 '13 at 15:04

Hamlet Hakobyan

score 3 · Answer 4 · answered Jan 04 '13 at 15:03

3

Nothing. Simply two different ways of writing the same thing

answered Jan 04 '13 at 15:03

Kevin

4 Answers4