MySQL

Einige hilfreiche Code-Fragmente:

CREATE ALGORITHM=UNDEFINED DEFINER=`wuerfl`@`localhost` SQL SECURITY DEFINER VIEW `propdm_ws09_cumulated_ratings` AS select
`propdm_ws09_ratings`.`aufgabenid` AS `aufgabenid`,
`propdm_ws09_exercises`.`bezeichnung` AS `exercise`,
count(`propdm_ws09_ratings`.`bewertung`) AS `count`,
sum(`propdm_ws09_ratings`.`bewertung`) AS `sum`,
avg(`propdm_ws09_ratings`.`bewertung`) AS `avg` from
`propdm_ws09_ratings` join `propdm_ws09_exercises` on `propdm_ws09_ratings`.`aufgabenid`=`propdm_ws09_exercises`.`id` group by `propdm_ws09_ratings`.`aufgabenid`;