Hi, i wouldlike to use aggregate functions in HQL, and i got such problems while experimenting with the query...
i have a class Booking like Booking(id, tutor,week,package,date,fee,term,note,student,order) i wouldl like to do a query as such : " "SELECT DISTINCT tutor, week, COUNT(DISTINCT student) AS numOfStudents FROM Booking WHERE term=:tm GROUP BY tutor,week" problem 1 is - the query does not work because i got an error telling me that group by clause must include all variables of this Booking class, i e , i changed my query to "SELECT DISTINCT tutor, week, COUNT(DISTINCT student) AS numOfStudents FROM Booking WHERE term=:tm GROUP BY tutor,week, id, package, date,fee,term,note,student,order" and it works. however, it seems that the query produces a list of Booking objects, not only the variables tutor, week, and numOfStudents as specified in the SELECT clause. as a result i got 2nd problem problem 2 - i actually defined another class called "Rota(tutor, week, numOfStudents)" and i did Rota t = (Rota) queryResult.get(0); and i got a ClassCastException. i guess the reason is that the query produces a list of Booking objects other than the only selected variables as in the select clause; therefore i changed to Booking b =(Booking) queryResult.get(0); unsurprisingly it doesnt work i guess its because in the select clause i have another variable "numOfStudnets" which is not defined in Booking. i dont know what to do... i certainly donot want to add a variable of "numOfStudent" to Booking class.. but i dont know any other solutions to this problems. seems HQL makes aggregate query much more complicated, or im doin this in totally wrong way? all in all, all i want to do is to get the values of "tutor, week, and numberOfStudents" from the query, nothing else. any ideas please help! thank you. -- View this message in context: http://www.nabble.com/use-aggregate-functions-tf2108930.html#a5813279 Sent from the Hibernate forum at Nabble.com. ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ hibernate-devel mailing list hibernate-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hibernate-devel
