I have a MySQL query that includes <> in it. I don\'t know the exact usage of it.
SELECT * FROM table_laef WHERE id = ? AND genre_type <> \'LIVE\'
<
<> means not equal to, != also means not equal to.
Documentation
In MySQL, I use <> to preferentially place specific rows at the front of a sort request.
For instance, under the column topic, I have the classifications of 'Chair', 'Metabolomics', 'Proteomics', and 'Endocrine'. I always want to list any individual(s) with the topic 'Chair', first, and then list the other members in alphabetical order based on their topic and then their name_last.
I do this with:
SELECT scicom_list ORDER BY topic <> 'Chair',topic,name_last;
This outputs the rows in the order of:
Chair
Endocrine
Metabolomics
Proteomics
Notice that topic <> 'Chair' is used to select all the rows with 'Chair' first. It then sorts the rows where topic = Chair by name_last.*
*This is a bit counterintuitive since <> equals != based on other feedback in this post.
This syntax can also be used to prioritize multiple categories. For instance, if I want to have "Chair" and then "Vice Chair" listed before the rest of the topics, I use the following
SELECT scicom_list ORDER BY topic <> 'Chair',topic <> 'Vice Chair',topic,name_last;
This outputs the rows in the order of:
Chair
Vice Chair
Endocrine
Metabolomics
Proteomics
<> is equal to != i.e, both are used to represent the NOT EQUAL operation. For instance, email <> '' and email != '' are same.
In MySQL, <> means Not Equal To, just like !=.
mysql> SELECT '.01' <> '0.01';
-> 1
mysql> SELECT .01 <> '0.01';
-> 0
mysql> SELECT 'zapp' <> 'zappp';
-> 1
see the docs for more info
<> is standard ANSI SQL and stands for not equal or !=.
<> means NOT EQUAL TO, != also means NOT EQUAL TO. It's just another syntactic sugar. both <> and != are same.
The below two examples are doing the same thing. Query publisher table to bring results which are NOT EQUAL TO <> != USA.
SELECT pub_name,country,pub_city,estd FROM publisher WHERE country <> "USA";
SELECT pub_name,country,pub_city,estd FROM publisher WHERE country != "USA";