MySql TIMESTAMP column is auto updated. Why?

Question

I have a table created with this SQL:

CREATE TABLE `test_table` (
  `id` BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  `data` TEXT,
  `timestamp` TIMESTAMP
)         


        

Answer 1

If you want that to your timestamp will be not added automatically ON UPDATE you have to define it like this

CREATE TABLE `test_table` (
   ...
   `timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP
) ...

Answer 2

Use a datetime field instead

Should I use field 'datetime' or 'timestamp'?

Timestamps in MySQL generally used to track changes to records, and are often updated every time the record is changed. If you want to store a specific value you should use a datetime field.

If you meant that you want to decide between using a UNIX timestamp or a native MySQL datetime field, go with the native format. You can do calculations within MySQL that way ("SELECT DATE_ADD(my_datetime, INTERVAL 1 DAY)") and it is simple to change the format of the value to a UNIX timestamp ("SELECT UNIX_TIMESTAMP(my_datetime)") when you query the record if you want to operate on it with PHP.