Hi,
Hi, I'm a novel developer of MySql and now I am trying to create a mysql
query to detect table updates.
I query a database table every X seconds, and i want to get only the
different rows in the table. The result that I want to have is simply
TABLE (t = now) - TABLE (t = X second ago)
Every time that i query the database I store the table situation in another
table, called TABLE_TEMP, so the operation of difference >detection is
TABLE_DIFERENCE = TABLE - TABLE_TEMP.
How can I do this query? The problem that I have is that I don't know the
structure of the table and I want to create a program with can be >used for
all types of data and tables.
Although in relational theory, a "relation" means the table or view and you
should be able to modify one relation to another, in SQL databases, it
doesn't work that way.
In SQL databases, a "table" doesn't get modified, you modify rows. A
table is nothing but a description of a certain structure. So in order to
know
if any row in a table has been modified, you either need to have some kind
of timestamp in each row or keep a copy of the table since it's last
modification
check.
Instead of querying the table, I guess you could write a trigger that
updates
a "metatable" that says a row has been added/deleted/modified for a
particular table.
With regards,
Martijn Tonies
Upscene Productions
http://www.upscene.com
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