need help to compare two columns in spark scala - scala

Question

I have spark dataframe like this
id1 id2 attrname attr_value attr_valuelist
1 2 test Yes Yes, No
2 1 test1 No Yes, No
3 2 test2 value1 val1, Value1,value2
4 1 test3 3 0, 1, 2
5 3 test4 0 0, 1, 2
11 2 test Yes Yes, No
22 1 test1 No1 Yes, No
33 2 test2 value0 val1, Value1,value2
44 1 test3 11 0, 1, 2
55 3 test4 0 0, 1, 2
val df = sqlContext.sql("select id1, id2, attrname, attr_value, attr_valuelist from dftable)
i want to check attr_value in attr_valuelist if it does not exists then take only those rows
id1 id2 attrname attr_value attr_valuelist
4 1 test3 3 0, 1, 2
22 1 test1 No1 Yes, No
33 2 test2 value0 val1, Value1,value2
44 1 test3 11 0, 1, 2

Answer 1

you can simply do the following with contains in your dataframe
import org.apache.spark.sql.functions._
df.filter(!(col("attr_valuelist").contains(col("attr_value")))).show(false)
you should have following output
+---+---+--------+----------+-------------------+
|id1|id2|attrname|attr_value|attr_valuelist |
+---+---+--------+----------+-------------------+
|3 |2 |test2 |value1 |val1, Value1,value2|
|4 |1 |test3 |3 |0, 1, 2 |
|22 |1 |test1 |No1 |Yes, No |
|33 |2 |test2 |value0 |val1, Value1,value2|
|44 |1 |test3 |11 |0, 1, 2 |
+---+---+--------+----------+-------------------+
If you want to ignore the case letters then you can simply user lower function as
df.filter(!(lower(col("attr_valuelist")).contains(lower(col("attr_value"))))).show(false)
you should have
+---+---+--------+----------+-------------------+
|id1|id2|attrname|attr_value|attr_valuelist |
+---+---+--------+----------+-------------------+
|4 |1 |test3 |3 |0, 1, 2 |
|22 |1 |test1 |No1 |Yes, No |
|33 |2 |test2 |value0 |val1, Value1,value2|
|44 |1 |test3 |11 |0, 1, 2 |
+---+---+--------+----------+-------------------+

Answer 2

You can define a custom function, user defined function in Spark, where you can test if a value from a column is contained in the value of the other column, like this:
def contains = udf((attr: String, attrList: String) => attrList.contains(attr))
def notContains = udf((attr: String, attrList: String) => !attrList.contains(attr))
you can tweak contains function how you want, and then you can select from your dataframe like this
df.where(contains(df("attr_value", df("attr_valuelist")))
df.where(notContains(df("attr_value", df("attr_valuelist")))