Merge pull request ktaranov#222 from hanucodes/master

Added SQL Queries Cheat Sheet Link

Author: ktaranov

README.md

@@ -155,6 +155,7 @@ Useful links, scripts, tools and best practice for Microsoft SQL Server Database
  - [Idera SQL Server Blog](https://community.idera.com/tags/SQL%2bServer)
  - [SQL Server Science Blog](https://www.sqlserverscience.com/) (by Max Vernon)
  - [Kohera SQL Server Blog](https://kohera.be/blog/category/sql-server/)
+ - [SQL Queries Cheat Sheet](https://helpercodes.com/sql-query-cheatsheet-tutorial/)
  - Security (great thanks to [Troy Hunt](https://www.troyhunt.com/troys-ultimate-list-of-security-links/)) <a id="security"></a>
  - SQL injection
  - [sqlmap - The tool for mounting SQL injection attacks tests against a running site](http://sqlmap.org/)