Thank you for the idea. That's the direction I was going. It does work, of course, I was just hoping for a more elegant solution.
PS (to OrientDB): It would be so nice if the Javascript engine used for functions supported ES6 template strings (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals). On Wednesday, June 1, 2016 at 11:44:36 AM UTC-5, Ivan Mainetti wrote: > > Hello, > > I think that the only way to do what you need is by using a function: > > I wrote this javascript: > > parameters: rid, map_name, key_name, key_value > > var g=orient.getGraph(); > > var sel=g.command("sql","select expand("+map_name+"."+key_name+") from "+ > rid+" where '"+key_name+"' in "+map_name+".keys()"); > > if(sel.length > 0){ > return sel[0] > } else { > var upd=g.command("sql","update "+rid+" put "+map_name+"='"+key_name+ > "',"+key_value+" return after @this."+map_name+"['"+key_name+"']"); > return upd[0]; > } > > then here's an example of usage: > > select > expand(function_name('#23:0','lista','key7',"{'Action':'Test22a','Enabled':false, > > '@type':'d', '@class':'Test'}")) > > > > > Il giorno mercoledì 1 giugno 2016 06:38:14 UTC+2, Eric24 ha scritto: >> >> I'm trying to determine the most efficient and least contentious way to >> do a sort of UPSERT on a LINKMAP property. Specifically, if I try to PUT a >> new item with a key value that already exists, I want the PUT to fail and >> leave the existing item in place (and instead return that item to the >> caller). By default, a PUT overwrites the key-matching item. I can prevent >> that with a WHERE clause, but I can't get RETURN to work (no syntax I've >> tried works). I can accomplish this doing a SELECT first, followed by a >> conditional UPDATE, but I'm hoping there's a more efficient way. >> >> Also, this is a very high-frequency operation (many potential update or >> update attempts to a given record per second). What happens to a single >> record with a LINKMAP (or EMBEDDEDMAP) property if one operation adds a new >> key/record and a concurrent operation adds a new different key/record? Are >> both keys/records retained or does the most recent update "win", >> effectively loosing the key/record added in the first operation or are both >> retained? If so, would locking the record during the operation solve that >> issue? >> >> -- --- You received this message because you are subscribed to the Google Groups "OrientDB" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
