数据库触发器将基于另一个触发更新一个表

Question

I have 2 tables

1. customer (which contains customer_id as primary key etc)
2. order1 (which also contains order_id as primary key, customer_id as foreign key)

I was asked to write a trigger to update order1's customer_id whenever customer table's customer_id was updated.

Please help me to find the answer. Please write me the query for the question.

If you want more information, reply me.

I have not tried this before because I don't know what to do very weak in triggers as well as in database.

I don't have any idea about these.

Answer 1

You can put pretty much any SQL you want in your trigger code.

For example a mysql trigger with a query which inserts data in a second table:

CREATE TRIGGER trigger_tru AFTER UPDATE ON some_table
FOR EACH ROW BEGIN INSERT INTO someotherdatabase.someothertable
SELECT * FROM some_table AS tablealias WHERE tablealias.primarykey=new.primarykey; 
END;