The logical model and/or physical design of a database.

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1answer
14 views

Good Schema model for this use case

It have following entity/data models: Service Provider --- Has Many(basically gives many) --- Services User Orders --- Has Many(can select many) --- Services (and it shall be having options to ...
0
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2answers
36 views

Integer ID vs varchar ID with JOIN

I have a table of users but I don't know what is the best practice between using a unique MEDIUMINT identifier or a unique pseudonyme identifier using VARCHAR. With MEDIUMINT identifiers, like the ...
0
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1answer
19 views

Relationship between data independence and database schema

What is the relationship between data independence and database schema? I know both of them separately. But I don't know how to explain the relationship of these two.
0
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0answers
9 views

Calculated field within report in Microsoft Access [migrated]

Shown below is my form so far, each student has taken two modules. What I wish to do is compare both pass/fail fields of both modules. If both are pass I wish the Pass/Fail box below to display pass. ...
0
votes
1answer
50 views

Creating a database for the first time, (I'm new at this) [on hold]

So first thing first. I basically a student worker for a college department for career success, which is brand new and starting from scratch. I am not a Computer Science major or developer by career. ...
-2
votes
0answers
21 views

One SQL Query on Product Database? [on hold]

Consider the following schema of a product database: Parts(pid, pname) Suppliers(sid, sname) Catalog(sid, pid) sid in Catalog is foreign key and reference to suppliers and pid in catalog is foreign ...
1
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1answer
620 views

Multiple product attribute inventory database design

I have a database to build based on inventory for my shop. This is the current data that I have put into tables. This is the package: This is the product attribute: This is the table ...
0
votes
1answer
26 views

MySQL - design help for scale

I will be using Amazon Web Services RDS service to host a MySQL 5.7 server (Currently AWS do not support 5.7, but they have announced they are working on implementing this version and it will be out ...
1
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1answer
25 views

Two tables with same field

QUESTION: I have QUOTATION table and SOA table quotation - table is for pending and not approve quotation. SOA- table for approve quotation. i will just transfer the data from quotation table to ...
0
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1answer
3k views

Storing multidimensional array in MongoDB

I am attempting to convert a large MySQL database of product information (dimensions, specifications, etc) to MongoDB for flexibility and to move away from the restriction of a column based table. I ...
-1
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0answers
26 views

Review this ER Diagram?

You have been asked to design a database for the university administartion, which records the following information: All students necessarily have a unique student ID, a name, and, a ...
0
votes
2answers
43 views

Database Design - Voting System

I'm creating a website in which people can submit there own lists, and then essentially others Up/Down Vote the items within the list. I'd like the list (If the submitter allows "votes") to be ordered ...
0
votes
1answer
18 views

Design - duplicating properties vs not allowing delete

I'm designing a database for a mobile app CMS that contains user data. These objects are Address and Job (a job can have 1 address and an address can have many jobs). The first version of a similar ...
4
votes
3answers
111 views

SQL - Many-to-Many relationship with same table and with relationship constraint

I have a SellerProduct table. Each row within the table represents product information as offered by a seller. The SellerProduct table has the following columns: id (serial, pk) productName ...
6
votes
1answer
990 views

Database table design question

Firstly, database novice here. I'm trying to create a system for processing Sales Orders into Purchase Orders and then split the Purchase Order into Shipping Containers. The systems needs to be able ...
3
votes
1answer
39 views

Explaining the problem with a column of values from a non-mutually exclusive domain

I'm trying to convince the powers-that-be that their current database design is risky and inefficient. I'd like to verify whether my assumptions are correct, and I'd like help in finding technical ...
0
votes
0answers
11 views

How can I make microsoft Access update fields that are linked in several tables?

I am working on a database for clinical observations in cancer mouse models. Usually, the animal care staff reports an observation that the vet checks. Sometimes, we have false positives that I need ...
0
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0answers
11 views

Question on comparing two fields in Access

I'm not sure if the title is fitting as I am not 100% sure if what I am doing is correct but here goes. Here is my enrolment table, I have added a field called pass/fail as you can see which is ...
3
votes
2answers
192 views

Database design of Room Booking system in a Hotel

Intro and System Description I am currently designing a Database for a Room Booking system in a Hotel. Client fills a Form / Request with following information about Room: amount of people in ...
0
votes
1answer
34 views

Query that compares dates

I'm trying to create a query that shows if students are mature or not, based on their date of birth. However when the query is executed it returns all students as not mature. Any students that are ...
0
votes
2answers
31 views

Can this be further normalized?

I have to define a system where we will be storing Image data and which can have an arbitrary number of attributes for the Image added per client. I have designed the following table Image ImageID ...
6
votes
1answer
184 views

Single table with more columns vs multiple tables with fewer columns

What would be a better database design for a social network website? A single table with more columns and fewer rows, or multiple tables with fewer columns but more rows? For example: A user can post ...
2
votes
1answer
28 views

Cascade deletes from multiple tables

I have a fairly standard restaurant model with a restaurant table in a PostgreSQL DB. All restaurants have ratings (which consist of average, vote_count and vote_sum) but in order to avoid repeating ...
0
votes
1answer
12 views

Access IFf Query

I'm new and just starting out at creating databases so I apologise if noob question. What I am trying to do is update my Staff table to show that "Sarah Avon" has married and her new last name is ...
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0answers
21 views

Relational database specialisation with constraints

Recently, I got the idea of inheriting in Relational databases, but I need to understand some things on which I'm not clear. So, let's suppose that we have these entities: Enterprise, BankAcount, ...
2
votes
1answer
33 views

What exactly is metadata? How is metadata different than regular data?

As I understand, metadata is data about data- so I think of analytics; is my simple definition correct? How is metadata different than data? I'm simply asking to broaden my understanding-thanks!
0
votes
1answer
136 views

How to setup sync between MongoDB and C# .NET Application

What is the best practice to synchronize a MongoDB remote database with a C# .NET App that would allow queries to be responded to within the local file system and update itself when there is a change ...
0
votes
1answer
125 views

How to predict the growth of a PostgreSQL database

I'm looking for a way to predict growth of the database given its fields, indexes, constraints (as foreign key), number of lines, and so. I searched on Google, but I found only means to determine the ...
0
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0answers
14 views

How to properly implement a relationship between a table with an array of foreign keys and the foreign table? [duplicate]

I'm not entirely sure how to implement this kind of relationship correctly. As an example, assume that we have: CREATE TABLE menu_item ( mi_name TEXT PRIMARY KEY, mi_ingredients TEXT[] ); ...
4
votes
1answer
53 views

Make a relation of a table with three different category of id's table

I have an issue There a table that's called "Routing" this table is for routing a task for three category of object - Analyser (interne machine) - subcontractor (externe ) Manually ...
0
votes
1answer
44 views

Store massive values data from remote controllers

I implemented telemetry system in order to observe state of remote objects. Every object has a controller collecting data from some sensors (about 10-30 controlled parameters, lets take average value ...
2
votes
1answer
46 views

Database design for cancer mouse models

This is a follow up question from my previous post: Does this simple database design work even if it's cyclic? I am a graduate student working on breast cancer. My mice are genetically ...
-1
votes
0answers
21 views

Writing SQL query for scenario [on hold]

I am trying to develope a shopping application. I need to write a query for the following table structures : enter image description here GRPMT : This contains the master group of Items(like ...
0
votes
0answers
29 views

how to desing a database for loan management in mysql [closed]

I am not very well experienced in database design . I designed database tables for user and account information `but in case of designing table for loan management and fixed deposits.` I want to ...
0
votes
0answers
36 views

Are my two proposed solutions on modelling resources inventory decent?

In the project management system that I am developing, I am wondering what is the best database design for keeping track of the resources inventory. While I want to determine what resources are ...
0
votes
4answers
86 views

Avoid using Many to Many Relationship

I have a 3 tables, Employee, Languages, Employee Languages. Now, Employee table is a profile table. Nothing special(Id, first name, last name etc.). Languages table has two columns: Language ID ...
3
votes
0answers
62 views

How to relate a [ parent common] table with (possibly many) subtype tables?

I am having a bit of a brain freeze. I have a table whose properties are the root of 4 distinct elements, for example: I need to relate SystemType to a SystemCommon, where one SystemCommon can have ...
3
votes
4answers
87 views

In a one-to-one relationship, where should the foreign key be placed?

I am currently designing an ERD for a project management system. I am unable to choose between two workable solutions as the best solution as I wish to embrace the best standards. The two entities ...
0
votes
1answer
274 views

Social file sharing database schema

I have a project called social media file sharing. I have this database schema and I need your opinion about what I should remove or add or edit on my database schema. Every user can upload media ...
0
votes
1answer
25 views

Every “INSERT” query check a combination of column's records

Unfortunately, my mind has stacked right now and i would like to design a really simple DB schema. What i want? In a simple table, for instance Table1, there are two different columns, Series and ...
3
votes
1answer
117 views

Multi-tenant database constraints

I have a multi-tenant app in PostgreSQL that has a repeated tenant_id column in each table to help isolate the tenants from each other. My question is, is there any sort of way that I can use ...
4
votes
2answers
56 views

Does this simple database design work even if it's cyclic?

I am a graduate student working on breast cancer in a veterinarian facility. I am designing a database to keep track of the health of my mouse colony. Each day, animal care staff verify each cage ...
0
votes
0answers
29 views

Sql multiple table checks for polling

I am implementing long polling using mysql for a near realtime data update for clients. Currently, this is what I have (and it works): A messages table, that holds messages between users,there is a ...
0
votes
1answer
39 views

Why do I need this attribute?

This is my relational schema; Book(title, shelfmark, ISBN, author, year) Genre(name) GenreBook(name, ISBN) User(firstName, lastName, cardID) UserBooks(cardID, ISBN, position) Why do I need the ...
3
votes
2answers
91 views

Survey Database - Respondent Table (1NF or 3NF - Pros and Cons)

Building out a Survey ERD ODS layer. Now i'm debating on the design for my Respondent Table. Not sure if its best to have it as 1NF or 3NF. FOr a quick back story I get a survey extract with ...
1
vote
2answers
151 views

novice-design: Are FOREIGN KEYs always necessary? Joins on columns which are not PK

I've been wondering if following approach is bad or really very bad:). Question#1: can we use indicator_id to combine data from indicator_values and indicator_details tables (without using FOREIGN ...
7
votes
1answer
160 views

Data Warehouse: How can i query daily snapshots?

I have some snapshots of a database that are not timeseries. For example: Snapshot day 1: +----+---------------+------------+------------+ | ID | Title | Category | Date | ...
2
votes
2answers
49 views

Is better to create a table for each room or make a single table that handles all the rooms in my case?

I need to make a server-side for iOS and android application that does something similar to chat(Is not really a chat), and I'm a PHP and MYSQL newbie. The process is that 2 users join a room and do ...
3
votes
5answers
328 views

How do I prove that the act of removing foreign keys doesn't corrupt existing data?

TL;DR: Prove that in practice, the execution of the alter table table_name drop foreign key constraint_name statement does not corrupt existing data. The important consideration is the execution of ...
0
votes
1answer
87 views

How to remove data redundancy in product table if multiple suppliers are there for same product

I am designing a database where I have different products and suppliers. For example, I have a product, "mobile phone", say an Apple 5S. This will be sold through my website from different suppliers ...