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Automatically Record Timestamps in MySQL

Automatic timestamp recording is a common requirement when maintaining records in a database. This article aims to address the specific question of how to configure MySQL to automatically store a timestamp when a new record is created, ensuring that the timestamp remains unchanged upon subsequent updates.

The initial approach attempted by the user involved using the timestamp data type with the current_timestamp as the default value. However, this method led to the timestamp being updated every time the record was modified, which was not the desired behavior.

The solution lies in using the DEFAULT constraint to set the timestamp to the current time only when a new record is inserted. Here's how it's done:

For a New Table:

At the time of table creation, include the following syntax:

CREATE TABLE ...
  your_date_column DATETIME DEFAULT CURRENT_TIMESTAMP
  ...

For Existing Tables:

If the table already exists, use the ALTER TABLE statement:

ALTER TABLE your_table
ALTER COLUMN date_column SET DEFAULT CURRENT_TIMESTAMP

With this configuration, the specified column will automatically receive the current timestamp without being affected by subsequent updates to the record.

Remember, leaving the date_column field empty will trigger the use of the default value (current timestamp), while specifying NULL or DEFAULT will also ensure the use of the default constraint. However, the column must be nullable for this approach to work effectively.

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