How to check if result of request to DB is empty?

[anonymous via Digitalmars-d-learn]

On 11.12.2015 22:05, Suliman wrote:
> I am using https://github.com/buggins/ddbc
>
> string query_string = (`SELECT user, password FROM otest.myusers where
> user LIKE ` ~ `'%` ~ request["username"].to!string ~ `%';`);

Don't piece queries together without escaping the dynamic parts. Imagine 
what happens when the user enters an apostrophe in the username field.

Also, are you using LIKE when authenticating the user? O_O

> How I can check if SQL request returned empty result?

When the result is empty, then rs.next() returns false on the first 
call, I presume.