Pronouncing SQL as es-kyoo-el is a rookie mistake. Sequel!
[1] https://dev.mysql.com/doc/refman/5.7/en/what-is-mysql.html
[2] http://www.postgresql.org/about/press/faq/
[3] https://social.msdn.microsoft.com/Forums/sqlserver/en-US/fd6...
This has led to some confusion.
Additionally, as I pointed out in a sibling comment up the chain somewhere, SQL is an abbreviation of the original acronym, SEQUEL, for Structured English QUEry Language. It seems with this provenance that the "sequel" pronunciation is more historically correct.