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<DIV><FONT face=Arial size=2>Hi everyone - hope you all had a good break. Looks
like summer has finally arrived (now that everyone's back at work)!
Anyway...</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I'm using Firebird (and transactions) for the first
time. I'm connecting to a remote database via the Firebird Server with no
problems, but I have a question about transactions:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>When I insert a new record, I use a trigger and a
generator to generate a new unique ID for the new record - I also query the
generator to see what the new value is that was returned by the trigger. The
code snippet is as follows:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face="Courier New" size=1> orderTransaction.Active
:= True;<BR> <STRONG>with</STRONG> orderQuery
<STRONG>do</STRONG> <EM><FONT color=#008000>//insert the
record</FONT><BR></EM>
<STRONG>begin</STRONG><BR>
ExecQuery;<BR> <STRONG>with</STRONG>
IBCurrentGeneratorValueQuery <STRONG>do</STRONG> <FONT color=#008000><EM>// this
query fetches the current value of the
generator</EM></FONT><BR>
<STRONG>try</STRONG><BR> Transaction
:= orderTransaction; <FONT color=#008000><EM>// share the same transaction
as the order</EM></FONT><BR>
Open;<BR> result:=FieldByName(<FONT
color=#000080>'newID'</FONT>).asInteger; <EM><FONT color=#008000>// get the
generator value</FONT></EM><BR>
<STRONG>except</STRONG><BR>
result:=-1;<BR>
<STRONG>end</STRONG>;<BR>
orderTransaction.Commit;<BR>
<STRONG>end</STRONG>;<BR></FONT></DIV>
<DIV><FONT face=Arial size=2>The question is, if multiple clients access the
database server at the same time, will <FONT face="Courier New"
size=1>IBCurrentGeneratorValueQuery </FONT>still return the correct value, or if
another concurrent transaction on another thread increments the generator, will
this query return the wrong value?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>When I was using MySQL (with PHP) I could use
mysql_insert_id() to query the new key value. I guess that if I could
get hold of the newly inserted row I could just get the field value, but the
same concurrency issue applies and I'm not sure how to get the record I just
inserted.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Cheers,</FONT></DIV>
<DIV><FONT face=Arial size=2>Phil.</DIV></FONT></BODY></HTML>