aggregate-functions

I'm experiencing a problem with MySQL's "GROUP_CONCAT" function. I will illustrate my problem using a simple help desk database: CREATE TABLE Tickets ( id INTEGER NOT NULL PRIMARY KEY, requester_name VARCHAR(255) NOT NULL, description TEXT NOT NULL); CREATE TABLE Solutions ( id INTEGER NOT NULL PRIMARY KEY, ticket_id INTEGER NOT NULL, technician_name VARCHAR(255) NOT NULL, solution TEXT NOT NULL, FOREIGN KEY (ticket_id) REFERENCES Tickets.id); INSERT INTO Tickets VALUES(1, 'John Doe', 'My computer is not booting.'); INSERT INTO Tickets VALUES(2, 'Jane Doe', 'My browser keeps crashing.');

This question already has an answer here: LISTAGG in Oracle to return distinct values 23 answers I have a table like this: group_id name -------- ---- 1 David 1 John 1 Alan 1 David 2 Julie 2 Charles And I want the following result: group_id names -------- ----- 1 'Alan, David, John' 2 'Charles, Julie' I can use the following query: select group_id, listagg(name, ',') within group (order by name) as names from demotable group by group_id To get this (very similar result): group_id names -------- ----- 1 'Alan, David, David, John' 2 'Charles, Julie' Any ideas how I can filter the names by

I have a sample table with similar structure & data as shown below: +------+---------+-------------+------------+ | S_ID | S_NAME | SUBJECT | MARK_VALUE | +------+---------+-------------+------------+ | 1 | Stud | SUB_1 | 50 | | 2 | Stud | SUB_2 | 60 | | 3 | Stud | SUB_3 | 70 | | 4 | Stud_1 | SUB_1 | 40 | | 5 | Stud_1 | SUB_2 | 50 | | 6 | Stud_2 | SUB_2 | 40 | +------+---------+-------------+------------+ Table has consolidated mark of each student in all subjects each that student has appeared. Please help me, to write a query to extract MAXIMUM mark obtained by each student ( irrespective of

I'm just learning MySQL - is there a way to combine (or nest) aggregate functions? Given a query: SELECT user, count(answer) FROM surveyValues WHERE study='a1' GROUP BY user; This will give me the number of questions answered by each user. What I really want is the average number of questions answered per user...something like: SELECT avg(count(answer)) FROM surveyValues WHERE study='a1'; What's the correct way to compute this statistic? If this is possible, is there a way to then break this statistic down for each question? (users can answer the same question multiple times). Something like: