So I have a disabled foreign key (Manager_ID in the table Employees) and I wanted to enable it, but I get this error: ORA-02298: cannot validate (my_username.EMP_MANAGER_FK) – parent keys not found And this is the code: Here’s how the table was created: Answer There are values in the column that are invalid from the foreign key’s perspective. Assuming that
Tag: foreign-keys
Define Position based on lowest ID and Foreign Key in MySQL
I am currently facing the following issue: I have 1 Table with my Broker Trading Data similar to this: The Goal is to say IF first OrderType (lowest Id where TradeId is the same) was a Buy, it’s a LONG Trade ELSE a Short Trade … output should be like this: What am I missing? How can I construct my
PostgreSQL / express rookie – create new table or just a new column in existing table? [closed]
Closed. This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 2 years ago. Improve this question This will probably get closed for being opinion based but hopefully I can get a comment or two. I’m building a social media app (Express/Postgres/React)
How to cascade on delete in a foreign key of a mysql table correctly?
I have three tables with foreign keys which should cascade on delete nevertheless when I run this only the mapping in Tagmap and nothing happens in Excerpt nor Tag. What am I doing wrong? Answer This is not how foreign keys work. You delete from the parent table (here, tag, or excerpt), and then children record are automatically dropped. If
Major bug in MySQL 8.x? — foreign keys
While retrieving foreign keys information from MySQL (for a code generator) I noticed this strange behavior. It looks like a major bug in MySQL 8.x. When I create a foreign key using REFERENCES the …
MySQL (Percona) Error 1452: Cannot add or update a child row for no reason
I have 2 Database Tables “users” and “tasks”. The tasks table contains two foreign keys for the createdBy_user_id and updatedBy_user_id columns both referencing users.id. If I try to insert an entry to tasks (after making sure the user referenced by the foreign keys exists) like this: The query fails with Error 1452: I don’t know why this happens, because everything
PostgreSQL cyclic foreign keys to multiple tables
I have 3 tables. chat_room group_chat_room private_chat_room As you can see chat_room has foreign key constraints that refer to group_chat_room and private_chat_room. Also both group_chat_room and private_chat_room have FK constraints that refer to chat_room. When I want to INSERT a row into group_chat_room I would use this However because of those constraints this would produce an error [23503] ERROR: insert
SQLite Delete row from Table A when columns are referenced as FOREIGN KEYS in other Tables B, C, etc
So I have several tables, but will show only 2 as an example: Table G gNo | gName | gAddress G1 | Jean | Bonalbo G2 | Oscar | Berlin G3 | Edd | Brisbane G4 | Bob | California Table B gNo | …
how to disallow custom lists to have elements from different base lists
I have the following model: BASE_LIST: in this table we store base lists. Base list can be for example the list of cities in a continent, types of automobiles in a shop etc. ELEMENT: in this table we store the elements of base lists. For example the cities and the car types are here (Budapest, London, Paris, Opel, Bmw, Audi)
Making sense of database table references with foreign and primary keys
I am relatively new to database logic, and am trying to figure out how multiple tables should/shouldn’t reference each other. I have a table, ‘Book’, that should have columns: I want each book to have the possibility to have 1 or more genres. I want each book to have the possibility to have 1 or more authors. I want each