May 2012
Intermediate to advanced
200 pages
3h 39m
German
Content preview from CouchDB kurz & gutBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Aufbau eines View
Ein CouchDB-View besteht aus zwei Komponenten, der Map- und der Reduce-Funktion. Die Reduce-Funktion ist optional und muss nicht definiert werden. Wenn Sie auf eine Reduce-Funktion verzichten, werden die Ergebnisse der Map-Phase ausgegeben.
Map-Funktion
Hier sehen Sie ein Beispiel für eine sehr einfache Map-Funktion:
function(doc) {
emit(null, doc);
}Diese Funktion erzeugt eine einfache Liste von sämtlichen Dokumenten in der Datenbank. Eine Map-Funktion wird von CouchDB mit einem einzigen Parameter aufgerufen. Dieser enthält das gerade zu verarbeitende Dokument. Auf die einzelnen Eigenschaften des Dokuments können Sie über die Punktnotation zugreifen. So können Sie zum Beispiel mit doc._id auf die ID des jeweiligen Dokuments zugreifen. ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.