Restrict users from changing rows inserted 3 hours ago in mysql

I inserted a number of rows 3 hours ago and I don't want these rows to change. How can I write a sql statement that will compare current time with the timestamp in the row开发者_JAVA百科 and restrict users from changing it if above criteria is met.

Thanks

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If you want to do it by using mysql, you will have to use the INTERVAL statement which will allow you to "add" time to date functions... for instance:

UPDATE table
SET data = 'whatever'
WHERE NOW() - INTERVAL 3 HOUR  < last_change

You can find more info and examples here: Date and Time Functions

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You can use a WHERE clause in all updates:

UPDATE yourtable
SET foo = bar
WHERE inserttime > NOW() - interval 3 hour