varchar to datetime mysql

hi,

i have huge db in which unknowingly i kept the column as varchar which actually has to be datetime. The data stored in it is in '16/September/2011' format.
Now i want to convert the data type to datetime without losing the data.
ie 2011-09-11 rest part can be ignored
is it possible?

db : mysql
programing language : php
LVL 15
InsoftserviceAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

 
johanntagleCommented:
http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html#function_str-to-date

in your case it should be STR_TO_DATE('16/September/2011','%d/%M/%Y')

0
 
Hugh McCurdyCommented:
Here's what I'd do.

1. Insert a new column.
2. Modify any software you have that uses the old field and change it to use the new field.  Hopefully you'll find everything.
3. Write a PHP program to read from the old column and write to the new column.  
3a. If the new column has data, I wouldn't overwrite it unless you are interested in the most recent date in which case, I'd overwrite it if not the most recent.  Why?  In case you don't find all instances that use the old field in step #2.

4. If you are absolutely certain that you don't have any software remaining that uses the old column (and you are absolutely certain you'll never need to revert to a prior version) then you can delete the old column.  Me, I'd keep the old column around for quite some time.
0
 
johanntagleCommented:
To complete the procedure:

1.  create a new date column
2.  run: update table_name set date_column= STR_TO_DATE(original_column,'%d/%M/%Y');
3.  drop the old column
0

Experts Exchange Solution brought to you by ConnectWise

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Cloud Class® Course: Python 3 Fundamentals

This course will teach participants about installing and configuring Python, syntax, importing, statements, types, strings, booleans, files, lists, tuples, comprehensions, functions, and classes.

 
johanntagleCommented:
Agree with hmccurdy's steps, except you don't need a PHP program for step 3.  To not overwrite on existing data, just do:

update table_name set date_column= STR_TO_DATE(original_column,'%d/%M/%Y') where data_column IS NULL;
0
 
johanntagleCommented:
data_column --> date_column
0
 
Hugh McCurdyCommented:
johan, you are correct.  I just like writing PHP programs.  
0
 
InsoftserviceAuthor Commented:
hi,

i had that code but with different format and thats the reason why it was not working i did not dropped so as to be in safe hand.
Thanx it worked
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.