A type of integrity constraint used in a RDBMS platform to ensure that a value in a column matches one of a range of key values from another table.

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How to Know Why Foreign Key Constraint Fails in MySQL

I'm using Laravel's Query Builder to put together some tables. I am trying to set up a foreign key, but it's failing with the following error: [PDOException] SQLSTATE[HY000]: General error: 1215 ...
3
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1answer
110 views

“Cannot resolve table name” error when applying MySQL dump to RDS

I'm setting up replication of an external MySQL instance to RDS. Both the external MySQL instance and RDS run MySQL 5.7.10. I've followed the procedure, but when dumping the database with mysqldump ...
4
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1answer
578 views

Why does Management Studio add the second alter table “CHECK CONSTRAINT” for a foreign key constraint

ALTER TABLE [dbo].[REMINDER_EMAIL] WITH CHECK ADD CONSTRAINT [FK__REMINDER_EMAIL__FACILITY_ID] FOREIGN KEY ( [FACILITY_ID] ) REFERENCES [dbo].[FACILITY] ( [FACILITY_ID] ) ALTER TABLE [dbo].[...
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2answers
377 views

Multiple relationships between the same entities

Is there a name for when 2 entities can have multiple relationships between them?
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1answer
39 views

sqlite3 foreign keys ignored

I am working on a small sqlite3 database for a small simple mailserver. I have created a new sqlite3 database and add executed this to pürepare it for data: BEGIN TRANSACTION; CREATE TABLE `mailboxes`...
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1answer
107 views

Foreign key with additional constraints?

There is a table called Item(id, name, cost) and Orders(id, bill_id, item_id, units), which is created to track orders placed, where same bill_id means it belongs to a single order. How to impose an ...
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1answer
43 views

Is inserting into a table with a foreign key constraint slower than inserting without constraint?

When using MySQL (actually, Aurora), will inserting into a table with a foreign key constraint be slower than the same table without the constraint?
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0answers
42 views

primary and foreign keys used in object-relational table

Currently I am designing an object-relational database based on an existing relational database with multiple primary and foreign keys, and was wondering if it is OK to use primary and foreign keys in ...
3
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1answer
125 views

Soft ON DELETE CASCADE

I am familiar with the ON DELETE CASCADE method, but I don't want to do a real delete, just a soft delete. This is implemented with a column named isDeleted (0/1). Is there a way for me to cascade ...
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1answer
89 views

Assign foreign key using one of two tables

Question 1: There are 3 Tables Direct Customers, Agent Customers, Sales Primary keys are marked in red underline: How to set foreign key for sales table using other two tables. I want foreign key ...
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1answer
26 views

MySQL getting errno: 150 on table creation from Workbench

I'm inexperienced with MySQL and I am trying to build a few tables and getting errno 150 which I believe could be to do with Foreign Keys. Here is my SQL as generated by Workbench. Thanks in advance ...
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1answer
84 views

Foreign key not working

This is a very basic foreign Key issue, I presume. Unfortunately I am not a dba so it is a bit baffling to me. I have two tables, Report and Request. The Report table has a primary key of [RP_ID], ...
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3answers
26k views

Difference between On Delete Cascade & On Update Cascade in mysql

I have two tables in MySQL database- parent, child. I'm trying to add foreign key references to my child table based on the parent table. Is there any significant difference between ON UPDATE CASCADE ...
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0answers
58 views

postgreSQL FK on delete set null not working

I want to set FK constraint on delete to null but it is not working. In table transactionauditlogentry I have altered the FK constraints for Packet and Credit table to on delete set null. If I ...
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1answer
124 views

SQL Server Management Studio: The columns in table do not match an existing primary key or unique constraint

I have two tables: Students and Courses. I want to set a foreign key in the Students table from the couseId column to the courseId column in the Courses table. I have set primary keys to both ...
3
votes
1answer
300 views

Table structure for validating data using category and subcategory fields

I am creating a simple budget application, and the primary table will be a transaction table that contains things like the amount of the transaction, date, account, the category and subcategory (the ...
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3answers
450 views

ORA-02270: no matching unique or primary key for this column-list

I getting an error report of: Error report - SQL Error: ORA-02270: no matching unique or primary key for this column-list 02270. 00000 - "no matching unique or primary key for this column-list" *...
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0answers
56 views

Should I move repeating foreign keys into separate table?

Idea Users can upload lots of items and send them from processing. From the upload settings I can set a channel to which the uploaded items belong to. Channel is a separate entity. Currently I set ...
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1answer
169 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: ...
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1answer
2k views

How to add FK on a column of composite type in PostgreSQL?

I have a table which contains a composite type and I am trying to connect a column of it to another table's PK. CREATE TABLE aaa (col1 SERIAL PRIMARY KEY); CREATE TYPE bbb AS (col2 INTEGER); CREATE ...
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2answers
599 views

Advice on a basic design, first time database design

I am taking a course to become a Java developer. The course involves using databases but we never really design any unfortunately. Most of the time we get pre-made databases and we have to implement ...
3
votes
1answer
84 views

Convert a lookup value to foreign key when a query is run

Currently we have a legacy system running queries on a Postgres server to update/insert records. One of the obstacles we are having is that we have to convert text values to the correct foreign key ...
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0answers
57 views

Foreign key violations detected upon UPDATE on another column

I have a table country that is referenced by many tables like so: db=# \d client Table "public.client" Column | Type | Modifiers --...
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1answer
56 views

SQL Query; Admin Log System; Foreign Keys; Retriving multiple rows form different tables at once

Table A (users) id | name | ip 52433 Yashas 1.1.1.1 512 Admin 5.6.7.8 Table B (admin_record) id | admin | time | date | reason | action 52433 512 2312352 ...
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1answer
20 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 ...
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4answers
295 views

Selecting data from another table using a foreign key [duplicate]

I have two tables A & B. Table A id | name | num Table B id | date | roll id in table B is a foreign key which relates to the id in table A. I want to get the contents of table B where id ...
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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 ...
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2answers
155 views

Is there any reason not to use foreign keys in MySQL?

I've never really used foreign keys before but I am building a project where they could come in handy. I have looked at some other large software such as some forum systems and they don't use foreign ...
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2answers
3k views

VARCHAR primary key - MySQL

Currently, I have a categories table with 2 columns - category VARCHAR(50) NOT NULL PRIMARY KEY and parent VARCHAR(50). The parent column is a foreign key (FK) to the category column. This seems like ...
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2answers
161 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 ...
3
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5answers
359 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 ...
5
votes
2answers
547 views

Foreign Keys doesn't work as I expect

Here are my tables; CREATE TABLE `borclular` ( `id` int(11) NOT NULL AUTO_INCREMENT, `tc` char(11) COLLATE utf8_turkish_ci NOT NULL, `borclu` varchar(255) COLLATE utf8_turkish_ci NOT NULL, ...
2
votes
1answer
64 views

Surrogate vs composite key in hierarchical data structure

I'm currently evaluating a schema for a hierarchical data structure. My main problem is how I should design the schema to prevent inconsistent data (reference of foreign key in another hierarchy). The ...
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1answer
83 views

Phpmyadmin / mysql error defining primary keys as foreign keys of two separate tables

I am designing a mysql database using phpmyadmin 3.3.10.4. Everything in the database is InnoDB. I have two tables, person with primary key person.id_numberand e-mail_address with pk e-mail_address....
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2answers
8k views

Why would a table use its primary key as a foreign key to itself

Looking through a database, I came across a table that used its primary key as a foreign key to itself. I've seen that a table can have a foreign key to itself to build a hierarchy structure, but it ...
0
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0answers
42 views

Cannot add foreign key constraint'?

Can someone please correct this code for me? When I click enter it says 'cannot add foreign key constraint'? CREATE TABLE entries ( Subject_id smallint auto_increment, Student_id VARCHAR(45) ...
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4answers
41 views

Foreign and primary keys question

I have have looked for an answer for my questions everywhere but they seem confusing to me.Can a foreign key be a primary key in the same table? Can a foreign key be a primary key in another table? ...
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1answer
67 views

Why does In-Memory feature not support foreign keys?

Why does Sql-Server 2014 In-Memory feature not support primary/foreign key relations? Can anyone explain what the problem with foreign key relationships and in-memory is? I guess just and only this ...
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1answer
27 views

Name of ForeignKey Back Relation?

Table detail has a ForeignKey to table master. How to call the back relation? master has ??? to table detail I could not find a canonical word in wikipedia or other resources.
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1answer
39 views

Replace content of only one table with new version (should disable foreign keys?)

I have 2 tables. 2nd has foreign keys to reference 1st. I need to replace the whole content of the 1st table with the new version from another database. The new version satisfies all constraints and ...
3
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0answers
64 views

How does mysql(innoDB) handle same foreign key for join

I have a table called X and another called Y. There is a primary key on Y that is a foreign key on X. Now, my data is such that there will be many rows in X that will have the exact same foreign key ...
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1answer
49 views

Postgres Can't Add Foreign Key Constraint

I have a table with about 220 million records :( and I need to add a foreign key constraint. My command looks something like this: ALTER TABLE events ADD CONSTRAINT events_visitor_id_fkey FOREIGN ...
0
votes
1answer
34 views

Do Foreign Keys Impose Uniqueness

Do FOREIGN KEYs impose the uniqueness of the the referent? I.e. if I have a foreign key that refers to a UNIQUE constrained column, will the FOREIGN KEY column be unique? I'm particularly wondering ...
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1answer
104 views

Index cleanup/usage help

My question is this: When running sp_blitzindex, I get a lot of these 2 warnings/suggestions: Index Hoarder: Unused NC index and Feature-Phobic Indexes: Potential filtered index (based on ...
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2answers
38 views

Recreate all foreign keys in all tables as deferrable (batch)

I want to make all foreign keys in my database deferrable. But there is no possibility to alter an existing constraint. So I need to drop and add again each foreign key. How to do it automatically?
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1answer
37 views

Cities and States (a few data): single table or splitted?

I am designing a DB schema and I need to store cities and states. I expect only a few rows, let's say, 20 cities. Example: id | city | state 1 | Rio de Janeiro | RJ 2 | Niteroi ...
12
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1answer
6k views

MATCH FULL vs MATCH SIMPLE in foreign key constraints

I've noticed a MATCH SIMPLE or MATCH FULL option in phpPgAdmin, but I can't find a description in the docs. The default is MATCH SIMPLE. How do they function?
3
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1answer
96 views

Store different rows type in single table

I'd like to create a DB to store different rows type. It will be kind of event list with time stamp. So I'd like to have an Event table with relations to other tables - each table will be a row type (...
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1answer
39 views

load data infile in mysql server 5.5 can't load data when foreign key exist

I have a database (TPC-DS benchmark base) with 24 tables(17 dimensions tables, 7 facts tables) I generated this database then I created it in mysql server 5.5 I used the instruction load data local ...
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37 views

Many-to-many relationship, what's the best choice for primary key? [duplicate]

In advance, I'd like to apologize if it's a duplicate question... I can't find a direct answer, probably because I'm not a native english speaker. Straight to the subject: I have 2 tables: company, ...