How to rename column names in spark SQL
<p>I have a dataframe with configurable column names eg</p>

<pre><code>Journey channelA channelB channelC
j1      1        0        0
j1      0        1        0
j1      1        0        0
j2      0        0        1 
j2      0        1        0
</code></pre>

<p>By configurable I mean there could be 'n' channels in the dataframe.</p>

<p>Now I need to a transformation in which I need to find the sum of all channels something like </p>

<pre><code>df.groupBy("Journey").agg(sum("channelA"), sum("channelB"), sum("channelC"))
</code></pre>

<p>The output of which would be :</p>

<pre><code>Journey sum(channelA) sum(channelB) sum(channelC)
j1      2             1             0
j2      0             1             1
</code></pre>

<p>Now i want to rename the column names to the original names and I could do it with</p>

<pre><code>.withColumnRenamed("sum(channelA)", channelA)
</code></pre>

<p>but as i mentioned the channel list is configurable and I would want a generic column rename statement to rename all my summed columns to the original column names to get an expected dataframe as :</p>

<pre><code>Journey channelA channelB channelC
j1      2        1             0
j2      0        1             1
</code></pre>

<p>Any suggestions how to approach this</p>