glamp · September 4, 2015 16:53 · Sep 4, 2015
diff --git a/mongodb-word-count.js b/mongodb-word-count.js
@@ -0,0 +1,28 @@
+var map = function() {  
+    var summary = this.message_soup_text;
+    if (summary) { 
+        // quick lowercase to normalize per your requirements
+        summary = summary.toLowerCase().split(" "); 
+        for (var i = summary.length - 1; i >= 0; i--) {
+            // might want to remove punctuation, etc. here
+            if (summary[i])  {      // make sure there's something
+               emit(summary[i], 1); // store a 1 for each word
+            }
+        }
+    }
+};
+
+var reduce = function( key, values ) {    
+    var count = 0;    
+    values.forEach(function(v) {            
+        count +=v;    
+    });
+    return count;
+}
+
+// full thing
+// db.support_emails.mapReduce(map, reduce, { out: "word_count" })
+
+// subset
+db.support_emails.mapReduce(map, reduce, {limit: 1000, out: "word_count" })
+db.word_count.find().sort({ value: -1 }).limit(10)