Re: Strange behavior with integer unsigned type...
Hello. That seems like a bug: http://bugs.mysql.com/bug.php?id=14543 Marko Domanovic wrote: mysql 5.0.15-standard UPDATE table SET fieldname = fieldname-1 when the fieldname is 0 gives me 4294967295 fieldname is integer(10) unsigned... maybe it would be more logical the expression to evaluate as 0, insted 2^32 .. -- For technical support contracts, goto https://order.mysql.com/?ref=ensita This email is sponsored by Ensita.NET http://www.ensita.net/ __ ___ ___ __ / |/ /_ __/ __/ __ \/ /Gleb Paharenko / /|_/ / // /\ \/ /_/ / /__ [EMAIL PROTECTED] /_/ /_/\_, /___/\___\_\___/ MySQL AB / Ensita.NET ___/ www.mysql.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Strange behavior with integer unsigned type...
Maybe it is because I am a programmer, but (unsigned) 0 - 1 = 4294967295. What's the big deal? Gleb Paharenko wrote: Hello. That seems like a bug: http://bugs.mysql.com/bug.php?id=14543 Marko Domanovic wrote: mysql 5.0.15-standard UPDATE table SET fieldname = fieldname-1 when the fieldname is 0 gives me 4294967295 fieldname is integer(10) unsigned... maybe it would be more logical the expression to evaluate as 0, insted 2^32 .. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Strange behavior with integer unsigned type...
mysql 5.0.15-standard UPDATE table SET fieldname = fieldname-1 when the fieldname is 0 gives me 4294967295 fieldname is integer(10) unsigned... maybe it would be more logical the expression to evaluate as 0, insted 2^32 .. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Strange behavior with integer unsigned type...
I noticed rather interesting thing... If you deduct 1 from the 0 which is stored in integer unsigned field, you get 2^32, not 0. I think that's how things are not working with version 4, and want to ask is this behavior bug or feature in mysql version 5, and is it customizable? Greetings, Marko -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Strange behavior with integer unsigned type...
Hello. On both 4.1.16 and 5.0.17 I've got the same results, however not 2^32, but 18446744073709551615. 4.0 is deprecated and its results could be different. Please provide exact SQL statement which you're using if you still think that MySQL behaves weirdly with unsigned integers. In the manual we have: mysql SELECT CAST(1-2 AS UNSIGNED) - 18446744073709551615 Marko Domanovic wrote: I noticed rather interesting thing... If you deduct 1 from the 0 which is stored in integer unsigned field, you get 2^32, not 0. I think that's how things are not working with version 4, and want to ask is this behavior bug or feature in mysql version 5, and is it customizable? Greetings, Marko -- For technical support contracts, goto https://order.mysql.com/?ref=ensita This email is sponsored by Ensita.NET http://www.ensita.net/ __ ___ ___ __ / |/ /_ __/ __/ __ \/ /Gleb Paharenko / /|_/ / // /\ \/ /_/ / /__ [EMAIL PROTECTED] /_/ /_/\_, /___/\___\_\___/ MySQL AB / Ensita.NET ___/ www.mysql.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Strange behavior with integer unsigned type...
I don't think that this behaviour is very surprising. If you carry out a mathmaticical operation that returns a result outside the data type's range then it _must_ give you an incorrect result. The only alternative would be to throw an error. I know that the manual documents that after an auto_increment column hits its maximum value it will 'roll over' to the lowest value that column will store (i.e. 0 for an unsigned int). Probably if you add 1 to 2^32 (or 2^16 for a SMALLINT, for example) you will get 0. BTW, 18446744073709551615 is the maximum value for a BIGINT (64 bit number), and IIRC MySQL uses 64 bit maths. FWIW my preferred web app middleware - Lasso - does the same thing (only with signed 64 bit numbers). HTH, James Harvard At 11:17 pm +0200 23/12/05, Gleb Paharenko wrote: On both 4.1.16 and 5.0.17 I've got the same results, however not 2^32, but 18446744073709551615. 4.0 is deprecated and its results could be different. Please provide exact SQL statement which you're using if you still think that MySQL behaves weirdly with unsigned integers. In the manual we have: mysql SELECT CAST(1-2 AS UNSIGNED) - 18446744073709551615 Marko Domanovic wrote: I noticed rather interesting thing... If you deduct 1 from the 0 which is stored in integer unsigned field, you get 2^32, not 0. I think that's how things are not working with version 4, and want to ask is this behavior bug or feature in mysql version 5, and is it customizable? -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
