I have three tables: conversations, user_messages and system_messages. Their basic structure (irrelevant columns removed for brevity) is: create table conversations(id int generated by default as identity primary key); create table user_messages( id int generated by default as identity primary key…
I need to adjust the following select statement to effectively filter out 523 records where 'first_date_purchased' is less than 'first_date_watched'. The following select statement returns 20778 records, of which 20255 should remain. SELECT se.student_id, si.date_registered, MIN(se.date_watched) AS first_date_watched, MIN(sp.date_purchased) AS…
to be more specific, I have a table with a list of symptoms and a table with a list of diseases. I have also created a table to link a specific symptom to a specific disease. What I'm looking to…
I want the solution like each item id all messages between sender and receiver and need all rows belongs to user i.e. if sender id = 3 and receiver id = 25 then it will list out all message of…
I'm using MySQL database. I have to join two tables (A, B). They have relationship (N->N). Actually, A is chatting room table and B is chat (chat record). Chatting room has many chats. If a user enters chat app, the…
Below is the database base snippet of the database that I am currently working on. Table transactions: id reference_table reference_field reference_id created_at 1 online_recharges online_recharge_id 10 2024-01-31 2 online_recharges online_recharge_id 11 2024-03-03 3 wallet_deductions wallet_deduction_id 10 2024-02-01 ... ... ...…
I have two tables 'poolTemp' and 'weather'. Both tables contain the columns "timeStamp" and "tempC". I want to join the tables with both "tempC" but only when poolTime.timeStamp is within 5 minutes of weather.timeStamp poolTemp.timeStamp data is recorded up to…
I'm looking for efficient strategies to optimize a MySQL query that generates Cartesian products in scenarios involving large data sets. The specific use case involves pairing cast and crew members for each movie in a database, which can result in…
I would like to select all active categories and view it with a breadcrumb. In my database I have the following: id_category category_name velleman_id velleman_parent prestashop_category prestashop_category_2 prestashop_category_3 prestashop_category_4 deleted 1 Car & Bike 10 0 2 Bike 10.10 10…
My JOIN does not work. The data stays NULL Hi, this is my first question, so please be nice. Think twice before hitting the "minus" button. 1/ I have a volatility AS bv table with he following fields: bv.Ticker bv.Vol_ref…