Asp.net – Correct way to approach composite foreign key
I have multiple classes X, Y, Z: public class X { public int Id { get; set; } public virtual List<Image> Images { get; set; } } public class Y { public int Id { get; set; } public virtual…
Postgresql – Postgres 11 not enforcing foreign key constraint?
Our PostgreSQL 11 database has tables A and B. postgres=# d A; Table "public.A" Column | Type | Collation | Nullable | Default ---------------------+-----------------------------+-----------+----------+--------- id | bigint | | not null | b_id | bigint | | not null |…
mysql – add foreign key constraint to a table
I have two tables name users , user_friends. user has over 10 million records and user_friends has more then 600 million records. The problem is that it does not have a constraint . i.e when a user is deleted their…
Mysql – Why Can't create table in this way?
I have a set of sql statements, CREATE TABLE PRICING( CodeVillage INT, TypeCabin INT, CodeSeason CHAR(2), WeekPrice INT, PRIMARY KEY(CodeVillage, TypeCabin, CodeSeason) ); CREATE TABLE SEASON( CodeSeason CHAR(2) PRIMARY KEY, NameSeason VARCHAR(20), CONSTRAINT Fk_Pricing_CodeSeason Foreign KEY (CodeSeason) REFERENCES PRICING(CodeSeason) );…
how to make relationship between to table in laravel?
my database has two table games and teams, games migration: $table->unsignedBigInteger('homeTeam'); $table->unsignedBigInteger('awayTeam'); $table->foreign('homeTeam')->references('id')->on('teams') $table->foreign('awayTeam')->references('id')->on('teams') what is relationship between this two table? many to many? should I create "game_team" pivot table? i tried to change design of database but it don't…
Postgresql – SQL – Best practice to refer two different table primary keys with the same foreign key?
I'm using PostgreSQL with the following (simplified) DB design: I have a table Auction, each auction can be handled from a Tribunal or a Court of Appeal. So that I have the table Court of Appeal (primary key = [id]…
Phpmyadmin – I want to automatically place the ID from the Parent table into a child table
I have two separate tables each will input the form data into the phpmyadmin Db respectively. Users and Parents respectively I am using procedural PHP and a prepared statement for form data. I have had success with each form inserting…
Postgresql – Virtual Foreign Keys in Postgres?
I've looked across a lot of Q&As for this, but haven't found any real answers, so I made this question. A lot of tech companies don't actually use foreign keys. Whether it be for easier migrations, or performance improvements, that's…
Postgresql – Filter rows by foreign key, but keep foreign data unchanged
Let's say I have a bands and a genres table who are connected through a join table called j_band_genres. Combined, this is my data: ID Names Genres 1 The Beatles Pop, Rock 2 The Rolling Stones Rock 3 Boney M.…
Phpmyadmin – How to Alter table with updating FOREIGN KEY
I am new in data base phpmyadmin Here my query that is giving error ALTER TABLE students ADD CONSTRAINT fk_enrollment_student FOREIGN KEY (student_id) REFERENCES enrollments (student_id); Here are structure of my table Table: students Table: enrollments Table: courses It is…