Question

I need a fast way duplicate a DATETIME column in a table and give it a new name.

I have a column named myDate in my table called myResults, I need a query to make a new column in the table called newDate which has the exact same data as the myDate column.

Is there a faster way to do this than by doing the obvious 2 step approach of make a new column, and then copying all the data (it’s a large table and I’m looking for the fastest approach)?

Obvious solution:

 ALTER TABLE `myResults` ADD `newDate` DATETIME;  
 UPDATE `myResults` SET `newDate` = `myDate`;

Answer 1

The obvious solution is the only solution, unfortunately.

However note that in general you shouldn’t be copying a column in relational databases.