I have a table like the following,
| id | name | color |
------+--------+---------
| 1 | pear | green |
| 2 | apple | red |
| 3 | banana | yellow |
| 4 | grape | purple |
I'd like to reorder alphabetically using the "name" column and reset the id (autoincrement) with this new order to end up with the following
| id | name | color |
------+--------+---------
| 1 | apple | red |
| 2 | banana | yellow |
| 3 | grape | purple |
| 4 | pear | green |
QUESTION: how can I do this with MYSQL?
Can I ask why you would want to do this?
If anyone modifies any of the name values or inserts new rows it will mess up your ordering scheme. Trying to store some meaning in the ordering of the PK that is already available elsewhere in the table (the name column) seems redundant and consequently a bad idea.
A much better solution is not to worry about the value of the ID column and just sort on the name column when you use the data in your app.
PS: Sorry for the non-answer type response. Normally I'd assume you had a good reason and just give an answer that directly addresses what you are trying to do, but I noticed from your other questions that you are still in the early learning stages about database design, so I wanted to help point you in the right direction instead of helping further your progress towards an ill-advised approach.