postgresql - Typecast string to integer

Question

I am importing data from a table which has raw feeds in Varchar, I need to import a column in varchar into a string column. I tried using the <column_name>::integer as well as to_number(<column_name>,'9999999') but I am getting errors, as there are a few empty fields, I need to retrieve them as empty or null into the new table.

Answer 1

Wild guess: If your value is an empty string, you can use NULLIF to replace it for a NULL:

SELECT
    NULLIF(your_value, '')::int