Ed Smith <[EMAIL PROTECTED]> wrote: > Greetings. When I execute the SQL script below in > mySQL 4.1, I get > > ERROR 1216: Cannot add or update a child row: a > foreign key constraint fails > > It is, of course, choking on the enroll row insert. > Why is this happening? Here are some things that make > the problem go away: > > 1. Take out the "name VARCHAR(30)" attribute from > student OR change the type to CHAR(30): In Section > 6.5.3.1 (second bullet), it says that if one attribute > is variable length, all attributes "silently" become > variable length. Does this mean student.sid is really > a VARCHAR? Could this be related to the problem? > > 2. Change type of enroll.sid to VARCHAR(5). > > 3. Change "Earl" to "Early" > > My theory: student.sid get "silently changed" from > CHAR to VARCHAR since student.name is VARCHAR; > however, enroll.sid does not change because there are > no variable length fields in enroll. This means that > > enroll.sid = "Earl " > student.sid = "Earl" > > Consequently, there is no match. > > Note that I did try specifying a length for the index > on sid (i.e., "INDEX sidindex (sid(5)),") but that > didn't help. Even shortening to 4 doesn't help, which > doesn't jive with my cohersion theory, assuming I > understand the index length specification. >
I tested your example and it worked fine for me. I didn't get any error. What is value of default-character-set? -- 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 -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
