Bug #8536 altering varchar columns after updateing from 4.0.x to 4.1.9

• Submitted: 16 Feb 2005 9:53
• Modified: 16 Feb 2005 14:50
• Reporter: Antony Mandilas
• Status: Can't repeat
• Category: MySQL Server
• Severity: S4 (Feature request)
• Version: 4.1.9
• OS: Windows (windows XP)
• CPU Architecture: Any

[16 Feb 2005 9:53] Antony Mandilas

Description:
Trying to execute both the queries with change and modify i get the following error :

BLOB/TEXT column '...' used in key specification without a key length

How to repeat:
having a table t with a column t1 which is currently varchar try to execute the following.

ALTER TABLE t CHANGE t1 t1 BLOB;

[16 Feb 2005 13:28] Heikki Tuuri

Hi!

Only prefixes of BLOB columns can be used in indexes. Please see the MySQL manual.

Regards,

Heikki

[16 Feb 2005 13:33] Antony Mandilas

Yes ok, but i am not trying to use any index.

i just want to convert a column from varchar to Blob, actually i try to follow the instructions of updating Char columns from 4.0.x to 4.1.9.

Best regards
Antony

[16 Feb 2005 14:34] Heikki Tuuri

Ok,

I am reopening this bug. Please show what

SHOW CREATE TABLE ...

prints.

--Heikki

[16 Feb 2005 14:50] Heikki Tuuri

Hi!

I am able to change a VARCHAR to BLOB.

I am putting this bug report to the state Can't repeat.

regards,

Heikki

heikki@hundin:~/mysql-4.1/client> ./mysql test
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 4.1.10-debug-log

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> create table t(a int not null primary key, b varchar(20)) type = innodb;
Query OK, 0 rows affected, 1 warning (0.11 sec)

mysql> insert into the values (10, 'jidhgjkdfidf');
ERROR 1146 (42S02): Table 'test.the' doesn't exist
mysql> insert into t values (10, 'jidhgjkdfidf');
Query OK, 1 row affected (0.00 sec)

mysql> alter table t change b b blob;
Query OK, 1 row affected (0.10 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql>