Fatal error: Uncaught PDOException: SQLSTATE[42803]: Grouping error: 7 ERROR: column "e.tema" must appear in the GROUP BY clause or be used in an aggregate function LINE 1: SELECT e.tema, e.leiras, e.versenynev,e.jelentkezesiHatarido... ^ in /var/www/html/app/libraries/Database.php:61 Stack trace: #0 /var/www/html/app/libraries/Database.php(61): PDOStatement->execute() #1 /var/www/html/app/libraries/Database.php(74): Database->execute() #2 /var/www/html/app/models/VersenyreszletekModel.php(22): Database->single() #3 /var/www/html/app/controllers/Versenyreszletek.php(16): VersenyreszletekModel->egyAdottEsemenyReszletei('1') #4 /var/www/html/app/libraries/Core.php(43): Versenyreszletek->index('1') #5 /var/www/html/app/require.php(16): Core->__construct() #6 /var/www/html/public/index.php(5): require_once('/var/www/html/a...') #7 {main} thrown in /var/www/html/app/libraries/Database.php on line 61