How can I return all columns in a table which contains only data with four characters or less?

Question

I'm mapping data from a MySQL table and have a table that has over 50 columns and over 100,000 rows, and I need to map a column that has data in it which has 4 characters or less.

How can I get a list of all columns in the table which have data that contains only four characters or less? In my case, all columns are varchar(255).

Answer 1

SELECT
  COLUMN_NAME

FROM INFORMATION_SCHEMA.COLUMNS

WHERE TABLE_NAME = <table>
AND CHAR_LENGTH(COLUMN_NAME) <= 4