Two questions about triggers and FK

古德里安

1 Can you use objects outside the database in the trigger, such as a table in a database (located on the same database server)
2.Can the FK of a table come from a primary key of multiple tables?
Means from a table, or from a table

Please help and tell how to achieve

fanfan1980

1 Can you use objects outside the database in the trigger, such as a table in a database (located on the same database server)


it should be OK

fanfan1980

2.Can the FK of a table come from a primary key of multiple tables?
Means from a table, or from a table

It's better not to be too fancy

couter

Tables that can trigger another database

古德里安

It's not even a heart ...
Now there are four kinds of devices, A, B, C, D
I put their data into four watches
Each device has its own unique ID, namely A.ID, B.ID, C.ID, D.ID
Now I want to have a table to store their failure information
Dev_ID may be the value of table A, maybe the value of table B, maybe ...
How to achieve this?
And they are not in the same database, but in the same server
Please help

sirenyun

This kind of business logic is best to use triggers to check, because you use the columns of multiple other tables to check the validity of a column of a table. Use triggers to implement your business logic when inserting or updating this column of this table!