chunni · November 15, 2016 22:46 · Jul 11, 2014 · Jul 11, 2014 · Jul 11, 2014 · Jul 11, 2014
diff --git a/Using cron to perform incremental Map-Reduce in MongoDB b/Using cron to perform incremental Map-Reduce in MongoDB
@@ -1,4 +1 @@
 Using cron to perform incremental Map-Reduce in MongoDB
-This is for the blog of:
-- [Perform incremental data aggregation with MongoDB's MapReduce and cron](http://meetfp.com/en/blog/mongo-mapreduce-cron)
-- [用MongoDB的增量MapReduce和cron实现增量计数](http://meetfp.com/zh/blog/mongo-mapreduce-cron)
diff --git a/Using cron to perform incremental Map-Reduce in MongoDB b/Using cron to perform incremental Map-Reduce in MongoDB
@@ -1 +1,4 @@
 Using cron to perform incremental Map-Reduce in MongoDB
+This is for the blog of:
+- [Perform incremental data aggregation with MongoDB's MapReduce and cron](http://meetfp.com/en/blog/mongo-mapreduce-cron)
+- [用MongoDB的增量MapReduce和cron实现增量计数](http://meetfp.com/zh/blog/mongo-mapreduce-cron)
diff --git a/Using cron to perform incremental Map-Reduce in MongoDB b/Using cron to perform incremental Map-Reduce in MongoDB
@@ -1 +1 @@
-Using cron to perform incremental Map-Reduce in MongoDB
+Using cron to perform incremental Map-Reduce in MongoDB
diff --git a/...perform incremental Map-Reduce in MongoDB → ...perform incremental Map-Reduce in MongoDB b/...perform incremental Map-Reduce in MongoDB → ...perform incremental Map-Reduce in MongoDB
diff --git a/init_tags.js → 1. init_tags.js b/init_tags.js → 1. init_tags.js
diff --git a/inc_tags.js → 2. inc_tags.js b/inc_tags.js → 2. inc_tags.js
diff --git a/init_tags.sh → 3. init_tags.sh b/init_tags.sh → 3. init_tags.sh
diff --git a/inc_tags.sh → 4. inc_tags.sh b/inc_tags.sh → 4. inc_tags.sh
diff --git a/cron_job → 5. cron_job b/cron_job → 5. cron_job
diff --git a/Using cron to perform incremental Map-Reduce in MongoDB b/Using cron to perform incremental Map-Reduce in MongoDB
@@ -0,0 +1 @@
+Using cron to perform incremental Map-Reduce in MongoDB
diff --git a/cron_job b/cron_job
@@ -0,0 +1 @@
+01 0 * * * /path/to/inc_tags_job.sh
diff --git a/inc_tags.js b/inc_tags.js
@@ -0,0 +1,27 @@
+//convert ISO data to ObjectId so that it can be compared with ObjectIds in db
+var ISODateToObjectId = function(date){
+    // Convert date to hex seconds
+    var hexSeconds = Math.floor(date.getTime()/1000).toString(16);
+
+    // Create an ObjectId with the hex timestamp
+    var id = ObjectId(hexSeconds + "0000000000000000");
+
+    return id
+}
+
+var conn = new Mongo();
+var db = conn.getDB("your_db");
+
+var start = new Date();
+start.setDate(start.getDate()  - 1)
+
+// The Map and the Reduce functions have been stored into system.js
+// and they can be used in the mapReduce function now 
+db.yeedd.mapReduce( mapTags,
+                    reduceTags,
+                    {
+                         query: { _id: { $gt: ISODateToObjectId(start) } },
+                         out: { reduce: "calc_tags" }
+                       }
+                     );
+}
diff --git a/inc_tags.sh b/inc_tags.sh
@@ -0,0 +1,3 @@
+# execute javascript file with mongo shell. 
+# please use your own file path and database path instead
+/usr/bin/mongo "localhost:27017/db"  /path/to/inc_tags.js
diff --git a/init_tags.js b/init_tags.js
@@ -0,0 +1,45 @@
+//The Map function, simply count tags
+var mapTags = function() {
+    if (!this.tags) {
+        return;
+    }
+
+    for (index in this.tags) {
+        emit(this.tags[index], 1);
+    }
+};
+
+//The Reduce function, accumulate the count
+var reduceTags = function(previous, current) {
+    var count = 0;
+
+    for (index in current) {
+        count += current[index];
+    }
+
+    return count;
+}
+
+var conn = new Mongo();
+var db = conn.getDB("your_db");
+
+//save the functions
+db.system.js.save(
+               { _id: "mapTags",
+                 value : mapTags
+                   }
+                 )
+
+db.system.js.save(
+               { _id: "reduceTags",
+                 value : reduceTags
+                   }
+                 )
+//execute the Map-Reduce, 
+//the results will be stored in the calc_tags collection
+db.yeedd.mapReduce( mapTags,
+                    reduceTags,
+                    {
+                      out: "calc_tags"
+                    }
+                  )
diff --git a/init_tags.sh b/init_tags.sh
@@ -0,0 +1,3 @@
+# execute javascript file with mongo shell. 
+# please use your own file path and database path instead
+/usr/bin/mongo "localhost:27017/db"  /path/to/init_tags.js
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		Using cron to perform incremental Map-Reduce in MongoDB
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		Using cron to perform incremental Map-Reduce in MongoDB