Hi Kevin, > I'm converting a database from a filesharing based technology to mySQL. The > database has its own column type called Sequence which is the same as using > the AUTO_INCREMENT property. I'd like to use AUTO_INCREMENT if possible but > I'm not really sure what I can do with it - can anybody help with the > following: > > 1. How does LAST_INSERT_ID() work? > Can I find out the last ID I created on a specific table and will this > return the correct value if multiple users are inserting into the tables?
Define "correct"!? It returns the ID of the row most recently INSERTed during this connection - which suits foreign key formation in secondary tables. This is distinct from providing the highest numbered ID currently in the table. RTFM: 8.4.3.126 mysql_insert_id() - which is not tremendously informative... > 2. I need to import data into the tables and do not want mySQL to re-create > the ID values for these records. How can this be achieved? Suggested approach: create the table(s) defining the ID field as a simple integer data type, and without any indexes or keys; perform the import; then use ALTER TABLE (or an administration package) to add the indexes and start off the AUTO_INCREMENT cycle from the correct ID value. RTFM: 6.4.3 INSERT Syntax 3.5.9 Using AUTO_INCREMENT 6.5.3 CREATE TABLE Syntax 6.5.4 ALTER TABLE Syntax Regards, =dn --------------------------------------------------------------------- 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
