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According to the docs, a delete+insert is exactly what is does: http://dev.mysql.com/doc/refman/5.1/en/replace.html http://dev.mysql.com/doc/refman/5.1/en/repla

by 0x0 13y ago

According to the docs, a delete+insert is exactly what is does: http://dev.mysql.com/doc/refman/5.1/en/replace.html http://dev.mysql.com/doc/refman/5.1/en/replace.html

Udo 13y ago
You're right. Sorry.
martin-adams 13y ago
Looks like you have to be careful of any ON DELETE CASCADE constraints as it could delete more than you bargain for.
- drawkbox 13y ago
  I agree. DELETING when you want to do an UPDATE or INSERT just seems wrong on all levels. DELETING is dangerous and I tend to prefer slightly slower performance of UPSERT with UPDATE/INSERT than involving a delete in the operation.
lazyjones 13y ago
That's what MySQL's REPLACE does, but not what "upsert" means: http://en.wiktionary.org/wiki/upsert http://en.wiktionary.org/wiki/upsert In presence of foreign key constraints for example, DELETE+INSERT might break/fail when UPDATE+INSERT will not. Also, the performance characteristics might be different.
- 0x0 13y ago
  Exactly, the original post (which seems to have been deleted) was claiming otherwise :)
- einhverfr 13y ago
  If foreign key constraints are deferred, they would be equivalent. It may not be perfect but it's a useful parallel I thought.