A schema of a database system is its structure described in a formal language supported by the database management system (DBMS) and refers to the organization of data to create a blueprint of how a database will be constructed (divided into database tables).

learn more… | top users | synonyms (1)

5
votes
2answers
482 views

Should we create a schema per “project”?

This is a database where users create a 'project' and work on it. We have a table for project and various other tables that contain different attributes for project (multiple rows for each project ...
0
votes
1answer
64 views

Does exist some software for transforming data from one DB schema to another?

I need to transform between two different database schemas the same data. For example i have one table in old schema like this: and i need to transform it to new schema like this: So i have few ...
0
votes
1answer
62 views

What is the name of the default schema in Oracle?

When you create an object in Oracle, and do not specify a schema (object prefix), is there a name for that default schema? I see in Oracle SQL Developer, that a newly created object shows up in the ...
0
votes
1answer
27 views

Database schema for timesheet app?

I am very new to database managements as I am enrolled in my first class involving databases at university. For my project, I have to create an app that clocks employees in an out and keeps track of ...
0
votes
0answers
17 views

Category of the same object in SQL and Inheritance.

I am trying to make the relational schema for a shop which sells ice creams and drinks. As the ice creams and drink both fall in the same category of Items, i tried making the items entity but i am ...
0
votes
0answers
22 views

Table design one or more

I am struggeling with the following issue. I have a table executives and supervisor, quite similar in the structure. Both of the executives can have a Car one or more. Should I make a table ...
0
votes
0answers
19 views

Database ERD for orders info

I have two tables: 1-orders order_id 2-shipping_and_billing order_id FK address_type(billing and shipping ) city I need to get full info of shipping and billing in single select of ...
3
votes
0answers
90 views

Best design to reference multiple tables from single column?

Proposed schema First and foremost, here is an example of my proposed schema to reference throughout my post: Clothes ---------- ClothesID (PK) INT NOT NULL Name VARCHAR(50) NOT NULL Color VARCHAR(...
1
vote
0answers
67 views

Database design in MySQL workbench

After doing some change As Mr Vérace told me here in this question, by changing the id names of each table into table_name_id and using the singular notation, I still need your opinion about this ...
1
vote
0answers
50 views

Manual postgres migration for Django (python) app

I have a Django (python) data model called Message: class Message(models.Model): text = models.CharField(max_length=50) sending_time = models.DateTimeField(auto_now_add=True) I added sender ...
1
vote
1answer
170 views

Database design for dentists

I have a homework, where I should create a database for a dental clinic using MySQL Workbench. This database will be used later for a web app for dentists. Here is a picture of the database design: ...
0
votes
1answer
36 views

Array or Object?

I am using MongoDB and designing a database. There is a list of itemCode. It won't change, but some new one will be added at some point. The total number of itemCode will never be over 100. Each ...
1
vote
3answers
85 views

Help with database schema design

I'm working on an Android application which utilizes a number of MySQL databases. The design is as such: Users have many recipes. Recipes have many ingredients Recipes have many directions I ...
0
votes
0answers
11 views

Restrict postgresql roles based on rows in upper level table

We have a postgresql database, and it is expanding to be used by more groups. The data from these groups will all live together in the same tables, but we need to restrict access to the data based on ...
1
vote
1answer
39 views

Login Schema Role User Setup

Environment: Windows Server 2012 SQL Server 2014 Standard Public website (Site-A) on Server Private website (Site-B) on Server Windows App running on workstations SQL Server 2014 Standard: 2 ...
6
votes
2answers
221 views

Efficient Database schema for multi-lingual content?

Assume I have a table for blog posts, posts, and schema as id author title content and each post can belonged to some categories id name descrtiption So a blog post can belong to multiple ...
3
votes
1answer
44 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
94 views

create table in a different schema

I am trying to create a table on a different schema without using "create any table" privilege. I have an application user/schema. TABLESPACE_NAME USEDMB MAXMB ----------------...
0
votes
0answers
44 views

Why default db privilleges are not applied on a new schema?

I have a user with all privileges granted by default in database properties. I create a new schema as postgres and table there. I expect that the user should have an access to this table but it looks ...
0
votes
1answer
29 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 ...
0
votes
0answers
29 views

Schema Design for multiple many-to-one relationships. of which exactly one should exist

Say I have table A, B, and C. B and C can both be related to multiple A's, but each A should have exactly one of either B or C related to it. Which database design is better: A: a_id, b_id NULL, ...
1
vote
1answer
40 views

Normalizing a folder schema

I've created a schema to allow creation of folders for customers. Customers Id Firstname Lastname StreetLine1 StreetLine2 City CustomerFolders Id CustomerId ParentId (NULL) Name Now as you can ...
1
vote
1answer
59 views

Database design for actions on some entity

I am making a todo list kind of a service. One todo list will have several items , that can be done/deleted/snoozed etc. Users can also add a new item to the list , delete an item etc. I want to ...
5
votes
1answer
249 views

ERD for a web development company

I am working on an ERD which represents the relationships between entities in a Web development company behavioral model. There I have entities like: Customer Service ----------- (like: web ...
2
votes
1answer
83 views

How unique are MongoDB _id fields?

I am trying to create a schema for documents and collections for a MongoDB database I am creating. I have read a few documents describing the _id field that is generated by each document upon creation....
3
votes
2answers
2k 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
147 views

Read-only user query in Oracle

I have been asked to create a read only user in a Oracle database 12c. The read only user must have read only grants only to the objects of select schemas, which I created and handed over. But now ...
1
vote
0answers
48 views

Design options for time series scientific data

I've been scratching my head over the last few days trying to find a solution that best suit my needs. I tried to think that what I want is probably not very different from what many others wanted ...
0
votes
0answers
27 views

Help creating database schema to build database off

not sure if this is the right area for a question such as this but I am looking to create a database for an IS warehouse who deliver laptops, desktops, monitors and other peripherals to different ...
3
votes
1answer
55 views

Seeking feedback on table relationships, general schema design

I'm designing a database for a business that sells tickets to a variety of events worldwide. The app will be built with Rails using PostgreSQL. Here's what I have so far, link to full size image I'...
1
vote
1answer
644 views

Schema design for products with multiple variants/attributes?

I'm using MySQL. The idea is similar to shopify with a different concept, so users are going to add their own products with multiple types of variants and attributes. From all the research I've done ...
0
votes
0answers
55 views

Database schema for storing edits in the content [duplicate]

I want to store all the edits of a specific table. Multiple fields can be modified and for different users. I want to store all changes, taking in count that the number of fields that can be edited ...
1
vote
1answer
33 views

SQL Server 2008 running schema query without identifiable cause

I am analyzing the performance on login to an application and in particular making sure the database response is acceptable. In running just the simple Activity Monitor I can see that there are two ...
0
votes
1answer
36 views

Can I create a unique constraint across schema in Postgres?

I have a task that I am trying to accomplish where the email address is unique. The email address is stored in the a3.user table as user_name. CREATE UNIQUE INDEX ix_user_user_name ON a3."user" ...
1
vote
0answers
24 views

UML database schema based on the creteria

I have the following requirements to design a database schema (brief): A Graphic Designer (we will call them designer) gets a call from a client with a new job to design a logo. The designer logs-...
0
votes
1answer
22 views

How to find functional dependancies from a relational schema?

If only given a schema (table header, with primary key indicated), how do i find functional dependancies? My problem is that would not functional dependancies depend on the data stored int he table, ...
1
vote
2answers
62 views

Why not have Persons for every person in schema?

I noticed that a lot of database schemas often show like, "students" or "teachers" or "employees" or "passengers" or something to that affect. Why not have a schema where every individual is a ...
0
votes
1answer
36 views

MongoDB storage of multi-dimensional arrays

Using MongoDB 3.0.7 as the primary datastore. I connect to it using ReactiveMongo 0.11 on a JVM-based language. My question is: how well does Mongo store multi-dimensional arrays? For image analysis, ...
3
votes
2answers
2k views

Schema Migration: SQL Server Data Tools vs Liquibase and Flyway

This might seem like a stupid question, but I've been looking into open source solutions for schema migration, namely Liquibase and Flyway. However, my boss told me that SQL Server Data Tools (SSDT) ...
0
votes
0answers
76 views

Hard dba case [schema to store delivery prices for shops]

I want to make a database scheme which would allow me to fetch the delivery price for the different Shops basing on the delivery destination (Address/Region) and order value (price). Here is the ...
1
vote
1answer
49 views

Active Directory group as a schema in SQL Server

In SQL Server 2008 R2 we have a database that is being maintained by a team of developers. Each of them should have permissions to perform DDL operations such as adding a column or creating a table. ...
1
vote
1answer
81 views

SQL Schema Change; Modification of Existing Table vs Creation of New

We are planning the data schema for our project. Currently we have a table with classifications, but there is the possibility of a new classification in the future which would require a new field to ...
0
votes
1answer
176 views

How would you design a table for approval system between User and Sports Club

I am currently learning database modelling and struggling to model the following requirement. I have a user and sports_club table. User can only join a sports_club if three existing users of the club ...
0
votes
1answer
49 views

Compare order of columns between two databases

I have two postgres databases which should have an equal db-schema, but have not. I want to see the difference in the column order. Columns of table1 in Dev: id, foo, bar Columns of table1 in Prod:...
0
votes
1answer
126 views

Single-Table vs. Multi-Table design

I'm trying to come up with a database schema which is going to be used for a social network similar to that of Facebook. Now for posts I have two schemas in mind which are as follows: Single-Table ...
0
votes
1answer
43 views

Default schema is ignored on SELECT

According to my understanding, a default schema should apply when issuing SQL statements on tables using unqualified table names. My problem is that the following statement fails, because the table ...
1
vote
0answers
25 views

DATE - Normalization, a multiple ranged query, multiple inserts and multiple update

I have a booking system, airbnb style. TABLES -> prices, house, available_date A house has available days and not available days, but sometimes the days have different prices. A weekend is more ...
0
votes
0answers
98 views

How can I layout a schema that will track monthly installments?

I'm pretty new to database design and have a beginner's understanding of SQL, mostly simple SELECT statements. I find myself in a situation where I have to create a system that will track monthly ...
0
votes
0answers
22 views

How can I organize this data?

I have been working in a system but don't know how to represent some of the data and its relations. There are three warehouses and a four shops working with the system and until this moment we can ...
0
votes
0answers
96 views

Finding the closure and super keys of a schema?

I am working on a problem in which I have to look at the relation R with schema R(w, x, y, z), and the three functional dependencies: w -> z ; x,y -> w ;z -> y For every non-empty subset X of ...