Question

I want to create a table with two column, one “created” and one “modified”, with a timestamp type. I don’t want them to have a default value. But when I create them, it automatically puts CURRENT_TIMESTAMP as default for at least one of them, and also on update.

How can I just have type timestamp with no default or on update value for any of my column?

Edit: I use MySQL

Answer 1

If you are using SQL Server, the timestamp type is used for row versioning, not for storing an actual date or time value. See MSDN.

You could create the columns with a datetime datatype and then set your created and modified values with triggers.

CREATE TRIGGER trg_SetDateCreated ON MyTable
FOR INSERT AS 
    UPDATE MyTable 
    SET created = CURRENT_TIMESTAMP
    WHERE MyTable.id = (SELECT Id FROM Inserted);
GO

CREATE TRIGGER trg_SetDateModified ON MyTable
FOR UPDATE AS 
    UPDATE MyTable
    SET modified = CURRENT_TIMESTAMP
    WHERE MyTable.id = (SELECT Id FROM Inserted);
GO