MySQL compare emails and match even if one upper the other lowercase

MySQL compare emails and match even if one upper the other lowercase

References

Reference NO 1

http://stackoverflow.com/questions/13584363/mysql-compare-emails-and-match-even-if-one-upper-the-other-lowercase

Reference NO 2

http://stackoverflow.com/questions/3150798/how-can-i-ignore-the-difference-between-upper-and-lower-case-when-searching-with

Reference NO 3

http://dev.mysql.com/doc/refman/5.0/en/string-functions.html

Reference NO 4

http://www.databasejournal.com/features/mssql/article.php/3655906

Reference NO 5

http://www.solutionoferror.com/mysql/query-for-student39s-marks-and-grades-in-moodle-13023.asp

Reference NO 6

http://www.electrictoolbox.com/article/mysql/order-updated/

Reference NO 7

http://docs.splunk.com/Documentation/Splunk/5.0.4/SearchReference/CommonEvalFunctions

Reference NO 8

http://www.maatkit.org/doc/mk-query-digest.html