MySql Query Replace NULL with Empty String in Select

Question

How do you replace a NULL value in the select with an empty string? It doesnt look very professional to output \"NULL\" values.

This is very unusual and based on my synt

Answer 1

The original form is nearly perfect, you just have to omit prereq after CASE:

SELECT
  CASE
    WHEN prereq IS NULL THEN ' '
    ELSE prereq
  END AS prereq
FROM test;