Missing value proper approach

Hello guys,

i would like to ask you how to deal correctly with missing value in KNIME.

Sometimes I have (correctly) missing values (it is not a mistake) and in KNIME Console I receive some warning message:

due to this there is Missing Value Node. For numbers I can fill with “0”, but how to deal with string contains "? " Leave “?” or use Missing Value Node and choose Do nothing or what is the correct approach?

Thank you in advance

Jiri

Hi @sm0lda,

well this depends on what are you doing with KNIME. Data science, data analysis/wrangling, ETL…? If missing value in String column produces missing value in String Manipulation node (for example you are using join() function) you can set it to blank (Empty string) using mentioned Missing Value node. Choose Fix Value and leave as it is.

Br,
Ivan

Well, I use KNIME as pure ETL tool. Mainly regex parsing some evaluation, enrichment and at the end output to csv and SQL type DB. Is there any potential risk if I do not Fix Values and write output to SQL DB?

Hi @sm0lda,

hmmm. Probably not but that again depends on what you want to have in your database. Null value or empty string? Only thing/risk that comes to my mind is if your column does not allow null values and you have such (missings) then writing to DB will fail.

Br,
Ivan