使用MySQL的select语句是否可能触发？

Question

I know that triggers can be used on insert, update and delete, but what about a trigger (or sort of) on a select statement. I want to use a trigger to insert data on a table B when it is selected an existent record on a table A, it could be possible?.

Thanks in advance.

Answer 1

您应该设计应用程序，以便仅通过某些方法可以进行数据库访问，并在这些方法中添加所需的监视。

Answer 2

It is not possible in the database itself.

However there are monitoring/instrumentation products for databases (eg for Sybase - not sure about MySQL) which track every query executed by the server, and can do anything based on that - usually store the query log into a data warehouse for later analysis, but they can just as well insert a record into table B for you, I would guess.

Answer 3

Not exactly a trigger, but you can:

CREATE FUNCTION myFunc(...) BEGIN INSERT INTO myTable VALUES(...) END;

And then

SELECT myFunc(...), ... FROM otherTable WHERE id = 1;

Not an elegant solution, though.

Answer 4

You can write an application which will be monitoring the query log and doing something when a select occurs. A pretty crude way to solve the problem though...