I've just started to learn MySQL and I'm stuck at a seemingly simple query. I've got 5 tables for a course provider db. 2 of them being Courses and Disciplines. Courses table has got discipline ID but Discipline table doesn't…
Context: I've been creating a database for a class assignment, the assignment doesn't have detailed instructions, instead gives us a narrative in order to have us make our own assumptions and interpretations as to what to create for the database.…
I keep running into this one over and over again, and seeking if there is a better (much more optimized) way to achieve this. Requirement : From a table XYZ select a random n rows (n can be one or…
I have a table that keeps track of runs. It has the following columns: ID distance run_time run_date 1 10 01:35:00 2023-12-10 2 10 01:48:00 2023-12-16 3 10 01:25:00 2023-12-17 4 10 01:41:00 2023-12-23 I want to calculate the average…
$rooms3 = Room::join("notifications", "notifications.room_id", "rooms.id") ->where('rooms.user_id', Auth::user()->id) ->join("watt_histories", "watt_histories.notification_id", "notifications.id") ->where('notifications.id', 'watt_histories.notification_id') ->latest('watt_histories.created_at') ->first(); If the query runs well, the return given is not null
Imagine a table that looks like | sender_ID | Receiver_ID | message_ID | , say table name is **tb** now I want to write an SQL query that gives me : user_id, Total messages exchanged by that user . So…
I will have to produce a result set which returns the month in each year that produced the highest sales? The tables of interest would be the products table, the order table and the date-time table. The current ERD for…
I have a postgres db that runs on an AWS RDS instance. It contains a somewhat complicated materialized view (created by four left joins). I would like to drop it but the query never completes (no error message, it seems…
I have an Athena table with a string column which looks like: +-------------------+ | employee_size | +-------------------+ | GREATER THAN 2000 | +-------------------+ | 500 - 999 | +-------------------+ | 28.00 | +-------------------+ | unknown | +-------------------+ | 563 |…
Context I have the table (hs_buildings) in my Postgresql DB containing the Point location of my buildings (hs_buildings.coordinates). Then I have a raster containing the land use in stored in a Postgresql raster table (named hs_raster_values). The resolution of the…