How to get column values which are changed after groupby applied?

Motheri Yani :

I am working on a spark code using java , where after join condition we got multiple records because of duplicate IDs in different sources,(ID are duplicates but some attribute changed) so with same id we have multiple records.what I need is to combine which are duplicates records to on single unique row for each ID

Input Dataset

+---+---+---+----+---+---+
|id |b  |c  |d   |f  |g  |
+---+---+---+----+---+---+
|1  |e  |dd |ddd |34 |r5t|
|1  |e  |dd2|ddd |34 |r5t|
|1  |e  |dd3|ddd |34 |rt |
|2  |e  |dd |ddd1|34 |5rt|
|4  |e  |dd |ddd1|34 |rt |
|1  |e  |dd4|ddd |34 |rt |
|4  |e  |dd4|ddd |34 |rt |
|4  |e  |dd4|ddd |3  |rt |
|2  |e  |dd |ddd |3  |r5t|
|2  |e  |dd |ddd |334|rt |
+---+---+---+----+---+---+

expected output

+---+--------------+--------------+--------------+-------------------+--------------+
|id |f             |            b |             g|d                  |d             |
+---+--------------+--------------+--------------+-------------------+--------------+
|1  |[34]          |[e]           |[r5t, rt]     |[dd4, dd3, dd2, dd]|[ddd]         |
+---+--------------+--------------+--------------+-------------------+--------------+


I tried giving explicitly collect_list as below

df.groupBy("id").agg(


                 functions.collect_set("f"),
                 functions.collect_set("b")

                ).show(1,false);

But my case we have 300 columns, in the dataset that too columns may not be same, changing some times.

Yashwanth Kambala :

In Spark org.apache.spark.sql package, there is agg(exprs: Map[String, String]) method which accepts a Map<String,String> where key is name of column and value is sql.functions.

Dataset<Row> df = spark.read().format("csv").option("header", "true")
                .load("...");

Map<String,String> collect_MAP =  Arrays.stream(df.columns())
            .filter(f -> !f.equals("id"))
            .collect(Collectors.toMap(f -> f,f -> "collect_set"));


     df.groupBy("id").agg(collect_MAP).show(false);


result

+---+--------------+--------------+--------------+-------------------+--------------+
|id |collect_set(f)|collect_set(b)|collect_set(g)|collect_set(c)     |collect_set(d)|
+---+--------------+--------------+--------------+-------------------+--------------+
|1  |[34]          |[e]           |[r5t, rt]     |[dd4, dd3, dd2, dd]|[ddd]         |
|4  |[3, 34]       |[e]           |[rt]          |[dd4, dd]          |[ddd1, ddd]   |
|2  |[334, 3, 34]  |[e]           |[r5t, rt, 5rt]|[dd]               |[ddd1, ddd]   |
+---+--------------+--------------+--------------+-------------------+--------------+


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