Hi David,
Thanks for that trick! But until there I had no problems.....is code ok,
that modifies and saves the model? Cause it feels like the changes are
not saved.
thanks
Tobias
> Howdy,
>
> You can save some memory by using findMap:
>
> def joinOrders(o1: LimitOrder): Unit = {
> /* select all orders where status=NEW and where that.tradeType !=
> order1.tradeType */
> val newOrders =
> LimitOrderMetaObj.findMap(By(LimitOrderMetaObj.status, "NEW")){o2 =>
> Full(o2).filter(o2.tradeType.name <http://o2.tradetype.name/> !=
> o1.tradeType.name <http://o1.tradetype.name/>)}
>
> findMap applies the filtering operation as each row is pulled from the
> RDBMS... so you'll have fewer objects in memory.
>
> In terms of the remaining logic... I'm a little lost in your code...
> can you describe the logic? What gets updated under which conditions?
>
>
> On Wed, Jul 22, 2009 at 5:35 AM, Hannes <[email protected]
> <mailto:[email protected]>> wrote:
>
>
> Hi Lifters,
>
> It seems like I'm having problems to modify items that are already in
> the database. What I do is, first find the item, then set a new
> value to
> it and then save it. So far so good, or?
>
> Because its a expensive filter process to find those items to
> modify, I
> made a local copy of the sub-list that contains the most interesting
> items. This sub-list is processed further on and when I finally know
> which items to modify, I look those ones up in the database again and
> set the values. I hope it makes sence...
>
> thanks
>
> Here's the code:
>
> def joinOrders(o1: LimitOrder): Unit = {
> /* select all orders where status=NEW and where that.tradeType !=
> order1.tradeType */
> val newOrders =
> LimitOrderMetaObj.findAll(By(LimitOrderMetaObj.status,
> "NEW")).toList.filter(o2 => o2.tradeType.name
> <http://o2.tradeType.name> != o1.tradeType.name
> <http://o1.tradeType.name>)
>
> def decideByTradeType: List[LimitOrder] = {
> /* keep all orders where that.marketPoint <= order1.marketPoint
> * sort the list from lowest to highest marketPoint */
> if (o1.tradeType.name <http://o1.tradeType.name> == "BUY")
> newOrders.filter(o2 => o2.marketPoint.is
> <http://o2.marketPoint.is> <=
> o1.marketPoint.is <http://o1.marketPoint.is>).sort((s, t) =>
> s.marketPoint.is <http://s.marketPoint.is> < t.marketPoint.is
> <http://t.marketPoint.is>)
> /* keep all orders where that.marketPoint >= order1.marketPoint
> * sort the list from highest to lowest marketPoint */
> else //because there are only two different types! Its the same
> as: if (o1.tradeType.name <http://o1.tradeType.name> == "SELL")
> newOrders.filter(o2 => o2.marketPoint.is
> <http://o2.marketPoint.is> >=
> o1.marketPoint.is <http://o1.marketPoint.is>).sort((s, t) =>
> s.marketPoint.is <http://s.marketPoint.is> > t.marketPoint.is
> <http://t.marketPoint.is>)
> }
>
> var i = 0
> var done = false
> val remainingOrders = decideByTradeType
> while (i < remainingOrders.length && !done) {
> if (remainingOrders(i).lots == o1.lots) {
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> remainingOrders(i).id)).map(_.status.set("OPEN")) openOr 0L
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> remainingOrders(i).id)).map(_.save) openOr 0L
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> o1.id <http://o1.id>)).map(_.status.set("OPEN")) openOr 0L
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> o1.id <http://o1.id>)).map(_.save) openOr 0L
> done = true
> }
> if (remainingOrders(i).lots.is <http://lots.is> <
> o1.lots.is <http://o1.lots.is>) {
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> remainingOrders(i).id)).map(_.status.set("OPEN")) openOr 0L
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> remainingOrders(i).id)).map(_.save) openOr 0L
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> o1.id <http://o1.id>)).map(_.lots.set(o1.lots.is
> <http://o1.lots.is> - remainingOrders(i).lots.is
> <http://lots.is>)) openOr 0L
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> o1.id <http://o1.id>)).map(_.save) openOr 0L
> }
> if (remainingOrders(i).lots.is <http://lots.is> >
> o1.lots.is <http://o1.lots.is>) {
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> o1.id <http://o1.id>)).map(_.status.set("OPEN")) openOr 0L
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> o1.id <http://o1.id>)).map(_.save) openOr 0L
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> remainingOrders(i).id)).map(_.lots.set(remainingOrders(i).lots.is
> <http://lots.is> -
> o1.lots.is <http://o1.lots.is>)) openOr 0L
> LimitOrderMetaObj.find(By(LimitOrderMetaObj.id,
> remainingOrders(i).id)).map(_.save) openOr 0L
> done = true
> }
> i = i + 1
> }
> }
>
>
>
>
>
> --
> Lift, the simply functional web framework http://liftweb.net
> Beginning Scala http://www.apress.com/book/view/1430219890
> Follow me: http://twitter.com/dpp
> Git some: http://github.com/dpp
>
> >
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