Question

Further to my previous question (qv) …

I have already created the table(s) and populated with data. How do I set the prefix length to a very large value or remove it all togther, so that I don’t have this problem? There will never be more than a few thousand rows and only this applciation is running on a dedicated PC, so performance is not an issue.

Solution, please for either PhpMyAdmin, or just MySQL command line.

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Update: Can I just delete this index (or make it infinitely long)?

Hmmm, I would prefer to keep the unique index if I can. So, how to make it infinitely long?

Or should I redefine my text fields to be var_char with a limit to the length? (I do know the max possible lngth of the primary key)

mysql> describe tagged_chemicals;
+-------------+---------+------+-----+---------+-------+
| Field       | Type    | Null | Key | Default | Extra |
+-------------+---------+------+-----+---------+-------+
| bar_code    | text    | NO   |     | NULL    |       |
| rfid_tag    | text    | NO   | UNI | NULL    |       |
| checked_out | char(1) | NO   |     | N       |       |
+-------------+---------+------+-----+---------+-------+
3 rows in set (0.04 sec)

Answer 1

It’ll probably be something like

CREATE INDEX part_of_name ON customer (name(10));

from create index documentation http://dev.mysql.com/doc/refman/5.0/en/create-index.html

where in your case the rfid_tag is length 20.