"Duplicate entry" problem

[george123456724]

Hi guys,

Have created a database using the MySQL control panel and phpMyAdmin. Nothing fancy, I'm just using it like an online Excel spreadsheet that can be updated by multiple users.

Everything was going great until this afternoon. I tried to add a new entry to the table, and I got the error:

"Duplicate entry '127' for key 1"

I kind of understand this - the entry would have been #127.

Each entry is assigned an auto-increment number which I use as a reference code. This field is the table's primary key.

Does anyone know why I am being prevented from adding entry #127?

I get the same problem both in mySQL Administrator and phpMyAdmin.

Thanks,

GeorgeC

 

[Guest_imported]

being #127, my guess is that your auto_increment field might be of type tinyint signed. If this is the case, any number over 127 is treated as 127, so you can't add anymore.

 

[george123456724]

Thanks very much Hung-Hsun Su - you're right.

It's working fine now.

Just out of interest, do you know what the maximum values are for smallint, mediumint, int and bigint?

 

[Guest_imported]

tinyint - 8 bits (-128 to 127 ro 0 to 255 depending on signed/unsigned)
smallint - 16 bits
mediumint - 24 bits
int - 32 bits
bigint - 64 bits