I'm trying to come up with a good database design for this use case I have a table called expenses as follows id category_id item_id Problem item_id column wouldn't make sense if the expenses category is i.e. "Rent" It would…
Let's say I have a database with columns name, last_name and type They're all strings, though type can only be TYPE_A, TYPE_B or TYPE_C I want a row in the database to be Unique when name and last_name already exist.…
I'm using MySQL and have a table with name Music that has tracks information like title,duration and ... This table also has "total_hit" column that it's value will be updated frequently by each track played(+1) : id title duration ...…
I have a table that read day_sunday, day_monday, etc... So I need to check that for today's column if value is true then what data is stored. For example 17 may => Wednesday so the query will be select *…
I am working on a project, in which I have used mongoDb as database. I am working on the cron, in which there was high mongoDb input/output operations, i.e. there was around 10k/s i/o operations on mongoDb including get, insert…
I have a MYSQL InnoDB table table with the following columns (table and column names changed): date (PK, DATE) var_a (PK, FK, INT) var_b (PK, FK, INT) rel_ab (DECIMAL) where rel_ab is a column that describes a relationship between 2…
The information found in the official MySQL documentation at https://dev.mysql.com/doc/refman/8.0/en/data-dictionary-file-removal.html does not match the information shown in the manual at https://dev.mysql.com/doc/refman/8.0/en/column-count-limit.html for version 8. First link says that the 64kb limit was dropped, the 2nd link says it exists. It…
I am trying to set up a database design with assets which have a number of distinct IDs, for example: CREATE TABLE IF NOT EXISTS assets ( id UUID PRIMARY KEY DEFAULT gen_random_uuid(), rl_id INT NOT NULL, unique_id VARCHAR(9) NOT…
I have a users table, with the primary key being an id field, which is an autoincrementing integer. I don't have a username field right now, but I would like to add one. Now, the username should be UNIQUE and…
I'm new to Databases and I started using PostgreSQL recently, I was wondering where, when and why should I choose Json and Jsonb type for my columns? In which cases using Json type is better and in which cases it's…