CASE WHEN option in MySQL

MySQL will return conditional based values without using if condition. Without using if conditions, we can use CASE WHEN option in MySQL.

For example,

For example: table name: students

sno	name	mark
1	Sachin	39
2	Dravid	90
3	Kohli	30
4	Ganguly	66

Output: Pass mark is above 40

sno	name	result
1	Sachin	Fail
2	Sachin	Pass
3	Kohli	Fail
4	Ganguly	Pass

Query:

SELECT sno, name, CASE WHEN  mark >= 40 THEN 'Pass' ELSE 'Fail' END AS Result FROM student

Pass the form values from one domain to another domain with POST values.

yes. we can pass the form values from one domain to another domain with using POST method. We have to add action attribute in <form> tag.

<form method="POST" action="http://www.anotherdomain.com" target="_parent">

</form>

Restrict cut, copy and paste in text area using Jquery

HTML:

<textarea id="textarea_id" > </textarea>

Script:

$(document).ready(function() {

$('#textarea_id').bind('cut copy paste', function(e) { e.preventDefault(); });

});

Remove or Delete duplicate records in a table in MySQL

Remove the duplicate records in a table, it will delete records which is having greater than the sno

For example: table name: players

sno	name	coach_id
1	Sachin	1
2	Sachin	5
3	Kohli	1
4	Ganguly	2
5	Kohli	4
6	Gambir	3

Query:

DELETE FROM players USING players , players AS virtualtable

WHERE players .sno > virtualtable.sno

AND players .name = virtualtable.name

Output:

sno	name	coach_id
1	Sachin	1
3	Kohli	1
4	Ganguly	2
6	Gambir	3

Display limited records with out using LIMIT in MySQL

If you want to get display limited records with out using LIMIT option in MySQL.

For example: table name: players

sno	name	coach_id
1	Sachin	1
2	Dravid	5
3	Kohli	1
4	Ganguly	2
5	Sehwag	4
6	Gambir	3

Query:

SELECT one.sno, one.name FROM players AS one

WHERE ( SELECT COUNT(*) FROM players AS two WHERE two.sno <= one.sno ) <= 3

Output:

sno	name	coach_id
1	Sachin	1
2	Dravid	5
3	Kohli	1