Question

Can someone give me an example of how to remove anything after a dash “-” in a zip code field using SQL commands?

For example, change any of this:

XXXXX-X
XXXXX-
XXXXX-XX
XXXXX-XXXX

to this:

XXXXX

Thanks for the examples. I also need to remove any instances of “-“, “-X’, “-XXXX”, etc in the databases so the zip codes just contain five digits. Can someone include an example of this?

Answer 1

Instead of using a regex, you could use MySQL’s SUBSTRING_INDEX() method:

SELECT SUBSTRING_INDEX(zip_code, '-', 1) FROM your_table

EDIT (to support updates)

UPDATE your_table SET zip_code = SUBSTRING_INDEX(zip_code, '-', 1);

I’d recommend creating a second column, maybe zip_code_short and running SET zip_code_short = instead of overwriting the main data – just to make sure it doesn’t cause any errors first (if feasible).