RE: Can a database get stomped by simultaneous access?
This WebDNA talk-list message is from 1997
It keeps the original formatting.
numero = 13039
interpreted = N
texte = Curt -Yes, WebCatalog should always perform the database operations for that template completely before doing them again for another request, even if they come in at the same time; it's smart enough to prevent your databases from getting munged up for simultaneous requests. Are you seeing two entries for the same cart number despite the [HideIf] context?thanks,Marc Eagle StarNine Technologies http://www.smithmicro.com/>We use a database to maintain an incremental counter we use as an invoice >order number with our webcat online orders, but we have had problems in >which every so often (we suspect it could be when we need to restart) we >get duplicate numbers for the counter in that database. The >ourDBs/Invoice_Counter_No.db contains just two fields [CART] and >[InvoiceNo] it started with a 0 value for a cart (which gets replaced by >the cart generated by webcat) and the desired invoice number we wish to >start from when we brought our online system up. > >Below is a sample code snippet of what we do: > >[CLOSEDATABASE ourDBs/Invoice_Counter_No.db] >[HideIf [lookup >db=OurDBs/Invoice_Counter_No.db&Value=[CART]&lookInField=CART&returnField=C >ART¬Found=0]=[CART]] >[Replace db=OurDBs/Inv_Receipt_No.db&eqCARTdata=0]CART=[CART][/Replace] >[Append db=OurDBs/Invoice_Counter_No.db]CART=0&InvoiceNo=[math][lookup >db=OurDBs/Invoice_Counter_No.db&Value=[CART]&lookInField=CART&returnFiel >d=InvoiceNo]+1[/math][/append][/Hideif] > > >The question is if we add a [closedatabase ourDBs/Invoice_Counter_No.db] >form after this operation could two customers simultaneously trying to >place an order stomp this database? Is webcat smart enough to keep a >database open if an operation is occurring on it even though another >customer may have hit the closedatabase form from another order? > >Curt
Associated Messages, from the most recent to the oldest:
Curt -Yes, WebCatalog should always perform the database operations for that template completely before doing them again for another request, even if they come in at the same time; it's smart enough to prevent your databases from getting munged up for simultaneous requests. Are you seeing two entries for the same cart number despite the
[hideif] context?thanks,Marc Eagle StarNine Technologies http://www.smithmicro.com/>We use a database to maintain an incremental counter we use as an invoice >order number with our webcat online orders, but we have had problems in >which every so often (we suspect it could be when we need to restart) we >get duplicate numbers for the counter in that database. The >ourDBs/Invoice_Counter_No.db contains just two fields
[cart] and >[InvoiceNo] it started with a 0 value for a cart (which gets replaced by >the cart generated by webcat) and the desired invoice number we wish to >start from when we brought our online system up. > >Below is a sample code snippet of what we do: > >[CLOSEDATABASE ourDBs/Invoice_Counter_No.db] >[HideIf [lookup >db=OurDBs/Invoice_Counter_No.db&Value=
[cart]&lookInField=CART&returnField=C >ART¬Found=0]=
[cart]] >[Replace db=OurDBs/Inv_Receipt_No.db&eqCARTdata=0]CART=
[cart][/Replace] >[Append db=OurDBs/Invoice_Counter_No.db]CART=0&InvoiceNo=
[math][lookup >db=OurDBs/Invoice_Counter_No.db&Value=
[cart]&lookInField=CART&returnFiel >d=InvoiceNo]+1[/math][/append][/Hideif] > > >The question is if we add a [closedatabase ourDBs/Invoice_Counter_No.db] >form after this operation could two customers simultaneously trying to >place an order stomp this database? Is webcat smart enough to keep a >database open if an operation is occurring on it even though another >customer may have hit the closedatabase form from another order? > >Curt
Marc Eagle
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