All Questions
2,344
questions
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Need to determine whether different question types for a questionnaire are many-to-many or one-to-many
We need to survey our contacts by asking them various questions and recording their responses. Some questions are standard and must be included in every survey (default questions), while others are ...
- 1
-3
votes
2
answers
54
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one-to-one mandatory attendance relationship
As shown in the diagram, there are 2 tables with a one-to-one relationship and mandatory participation. Can you help me implement this as ddl code? I could do it easily when there was no mandatory ...
- 17
-1
votes
0
answers
26
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Real estate database design to save listings of different types [duplicate]
I am creating a website similar to this website. My website needs to allow users to save different kinds of listing like home, plots. offices, shops, agricultural land etc. My question is how to ...
1
vote
1
answer
69
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Merge many large tables in PostgreSQL
I have 150 tables with the same columns representing areas in a country. The size of each table is millions of rows and tens of GB in size.
I want to combine all the tables into one with the aim of ...
- 541
0
votes
1
answer
35
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Dependency Cycle in Database with Update Approvals
I'm struggling with a dependency cycle in my SQL database schema for a system with update approvals. Here's the situation:
I have tables for documents , transactions, payment_methods, and ...
0
votes
1
answer
36
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Designing SQL Postgres Relations Table for Editing Entered Documents and Undo Functionality
I'm currently working on a system where users can edit entered documents in a PostgreSQL database. The functionality entails allowing users to click on a document to edit it, effectively creating a ...
- 254
1
vote
1
answer
98
views
How to implement a wide multi-level self-join PostgreSQL query?
I have several rows that represent a person. Each person has a column for bio_mother _uuid and a bio_father_uuid. I used this page (I mention that because it's referenced in this similar question) to ...
- 198
1
vote
1
answer
75
views
Use conditional constraint or normalize table?
I have two entities: A and B. The latter has two types B1 and B2. Their relationship is:
(A,B1) is (1:1)
(A,B2) is (1,N)
When creating database tables, I wonder how is the best way to guarantee ...
- 62
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votes
1
answer
54
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Design SQL Schema for User Interests
I'm trying to find the best approach for designing sql schema for the following scenario:
-A User can have multiple interests
-The platform provides predefined interests from which the user can ...
- 1
0
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0
answers
59
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How to assign multiple Foreign keys to one box in an sql table
I have created a database that has one table that keeps track of employee skills and another which displays projects that these employees can be assigned to.
I need to have multiple employees asigned ...
user23579913
-2
votes
2
answers
56
views
How to delete only orphan child rows with ON DELETE?
I have a parent table and a child table. A parent row stores the foreign key to the child row. If I set the constraint on the foreign key to ON DELETE CASCADE then that will throw an error when I want ...
- 27
-1
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1
answer
83
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Separate tables based on business goals
Is it worth to split tables bases solely on the business goal?
NOTE: The tables all have identical columns.
1. One table
One orders table, with a orderType column to differentiate them.
2. Two tables
...
- 2,192
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0
answers
70
views
Were the entity sets and their associated relationships accurately and properly constructed?
To be considered:
The bolded terms that appear across the requirement I laid out bellow are the ones included in the entity set (Vehicle) I created.
I also specified the attributes nature/kind/type.
...
- 19
0
votes
1
answer
47
views
"Using index condition; Using where" explaining my query, with proper indexes?
From the manual Using index condition; Using where:
By accessing index tuples and testing them initially, tables can be
read while deferring the reading of full rows until it is essential.
I've the ...
- 48.3k
0
votes
1
answer
46
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Relational Database - How do you design SQL many to many relationship
What's the correct way to do (what I think is) a many to many association in a relational database?
Consider something such as (I'm using sqllite to play around):
# Store details about each teacher...
...
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