jwakely, Wednesday, September 18, 2002, 5:46:19 PM, you wrote: jamdc> The output of DESCRIBE tbl_name shows unique keys to be "MUL" for columns jamdc> defined as NULL.
jamdc> The SQL shown is a minimal test case that creates a new database and two jamdc> tables, both with a unique key on the column "uni" jamdc> The first table is fine. jamdc> The second table "bug" shows the wrong output for "EXPLAIN bug", jamdc> the index on the second column is shown to be non-unique. jamdc> The only difference between the tables is whether the second column jamdc> is defined to be NULL or NOT NULL. jamdc> The result is exactly the same if the column type is VARCHAR, not INT. jamdc> Version 3.23.32 shows UNI in both cases, as I expect to see. jamdc> Version 3.23.49 shows the wrong output, as described in this bug report. jamdc> If this is actually the correct output, because a NULL column with a jamdc> UNIQUE key can contain multiple NULL values, then ignore this bug. jamdc> Instead the manual needs to be fixed to explain the output of this command. jamdc> Currently the manual contains circular references for "EXPLAIN tbl_name", jamdc> "DESCRIBE tbl_name" and "SHOW COLUMNS FROM tbl_name", none of the relevant jamdc> sections explain the output, they just refer you to one of the other jamdc> sections (I'll be raising this as a separate issue anyway). It's a correct output, bacause "MUL" means that column can contain same value(s) multiple times (in your case it's a NULL value). -- For technical support contracts, goto https://order.mysql.com/?ref=ensita This email is sponsored by Ensita.net http://www.ensita.net/ __ ___ ___ ____ __ / |/ /_ __/ __/ __ \/ / Victoria Reznichenko / /|_/ / // /\ \/ /_/ / /__ [EMAIL PROTECTED] /_/ /_/\_, /___/\___\_\___/ MySQL AB / Ensita.net <___/ www.mysql.com --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
