How to return 'NULL' in fields with no input in SQL? [duplicate]

Question

I have a table that has the following columns: year, city, country, avg_temp.

I am trying to write a query that extracts the data into a CSV, but I want the fields with no input to show NULL for avg_temp.

SELECT IF(columnName IS NULL, 'NULL', columnName) as columnName FROM table — Mm-Art-In
– Mm-Art-In, Commented Nov 28, 2020 at 19:06

Mm-Art-In · Accepted Answer · 2020-11-28 19:04:43Z

0

You can check in the select with

CASE WHEN avg_temp IS NULL THEN 'NULL' ELSE avg_temp END AS avg_temp

Or with if

IF (avg_temp IS NULL, 'NULL', avg_temp) AS avg_temp

Mm-Art-In

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answered Nov 28, 2020 at 19:00

Thallius

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