Comments on: MySQL Error 1170 (42000): BLOB/TEXT Column Used in Key Specification Without a Key Length

By: Eli Manobella

Eli Manobella — Thu, 30 Apr 2009 14:32:51 +0000

Thank you for the post.
I need a key that is longer then 256.

What can I do?

googling it for the past 3 hours with no luck…
(Paco Zarabozo comment did not work for me)

Preaching to the UTF8 converted at hontou ni sou omou? — Sat, 13 Dec 2008 14:20:27 +0000

[...] I ran into some problems, I back-pedalled to square one. Thankfully my backup restored the Latin1 database without any [...]

Paco Zarabozo — Wed, 29 Oct 2008 02:16:23 +0000

Well, here’s another solution. You can actually specify the key length for your index while keeping your field as longtext. This is an example:

create table messages (
id int(20) not null auto_increment,
message longtext,
index (message(996), id)
);

desc messages;
show index from messages;

996 is the maximium key length mySQL has accepted for me.

Cheers,

Paco

David — Mon, 27 Oct 2008 11:50:48 +0000

Thanks a lot!

Marius Vilaia — Sun, 05 Oct 2008 19:50:33 +0000

Thank you very much. I had this problem and you were a life saver!

Reza — Thu, 06 Mar 2008 20:15:54 +0000

Thanks, very good defined

Jamie Slater — Fri, 22 Feb 2008 19:40:22 +0000

Thanks for the post. Very helpful.

Ben Hardy — Tue, 19 Feb 2008 18:45:21 +0000

Thanks! Very useful post.

Felix — Thu, 30 Aug 2007 10:33:07 +0000

Thanks for putting this up. I didn’t get the error and you saved me a lot o frustration. I’d put you in the ‘Goog people’ category anytime