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Posted to user@spark.apache.org by Xuelin Cao <xu...@yahoo.com.INVALID> on 2014/12/15 10:27:40 UTC

Why my SQL UDF cannot be registered?

Hi,
     I tried to create a function that to convert an Unix time stamp to the hour number in a day.
      It works if the code is like this:sqlContext.registerFunction("toHour", (x:Long)=>{new java.util.Date(x*1000).getHours})

      But, if I do it like this, it doesn't work:
      def toHour (x:Long) = {new java.util.Date(x*1000).getHours}      sqlContext.registerFunction("toHour", toHour)
      The system reports an error:<console>:23: error: missing arguments for method toHour;follow this method with `_' if you want to treat it as a partially applied function              sqlContext.registerFunction("toHour", toHour)             Anyone can help on dealing with this error?

RE: Why my SQL UDF cannot be registered?

Posted by "Cheng, Hao" <ha...@intel.com>.

As the error log shows, you may need to register it as:

sqlContext.rgisterFunction(“toHour”, toHour _)

The “_” means you are passing the function as parameter, not invoking it.

Cheng Hao

From: Xuelin Cao [mailto:xuelincao@yahoo.com.INVALID]
Sent: Monday, December 15, 2014 5:28 PM
To: User
Subject: Why my SQL UDF cannot be registered?


Hi,

     I tried to create a function that to convert an Unix time stamp to the hour number in a day.

      It works if the code is like this:
sqlContext.registerFunction("toHour", (x:Long)=>{new java.util.Date(x*1000).getHours})

      But, if I do it like this, it doesn't work:

      def toHour (x:Long) = {new java.util.Date(x*1000).getHours}
      sqlContext.registerFunction("toHour", toHour)

      The system reports an error:
<console>:23: error: missing arguments for method toHour;
follow this method with `_' if you want to treat it as a partially applied function
              sqlContext.registerFunction("toHour", toHour)

      Anyone can help on dealing with this error?