Count Null value in the column

KNIME Analytics Platform
#1

Hi, I am very new to Knime tool and stuck at very basics itself. I have a table where I need to count null (for string datatypes) and 0’s(for Int data types ) in all the columns and get the error percentage of that.

Input is like below table:
column A
a
d
f
null
null
a
d
f

column B
12
10
0
89
45
2
1
12

I’m expecting that the output as:
Count of Null found in column A = 2
null error% for column A = (8-2/100 = 0.06 )
Same goes for column B for number of 0’s

1 Like
#2

Hi @rgupta01 -

I’m moving the topic to the main Analytics Platform forum for better visibility :slight_smile:

#3

Hi @rgupta01

I created a workflow count null_value in column.knwf (60.9 KB)

count_nill_value
count_nill_value1103×461 42.8 KB

This flow splits the data into 2 groups; strings and integers. Then every (string/integer) column goes through the same loop en identify the “0” and the “null” . Via an GroupBy node the percentage (or better the mean) is calculate to identify the partition of “0” and “null” . In the end all the results-columns are collected together. Does this help you?

gr. Hans

3 Likes
#4

@HansS, It worked really well. Thank you so much :slight_smile: I would be able to start now with Knime !!!

3 Likes
#5

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