Is there a function in SQL to replace an insert sql query values 'NULL' as NULL or 'unknown' as NULL

Question

I have constructed an insert sql query in Python. In python code, I have given 'NULL' string for a column value. While executing the sql query, database is inserted with value 'NULL' for the column. I want the column to be updated with NULL value. Similarly, I want to execute an insert sql query with value NULL for a value 'Unknown' constructed in python.

Here is my sql query:

INSERT INTO lookup SELECT 'Unknown' as dc, 'NULL' as URL FROM lookup_hierarchy lh WHERE lh.location = 'Arizona';

How to replace 'NULL' with NULL in sql ? How to replace 'unknown' with NULL in sql ?

Answer 1

您可以使用条件，该条件始终返回NULL例如：

INSERT INTO lookup SELECT IF(1, NULL, 'Unknown') as dc, IF(1, NULL, 'null') as URL FROM lookup_hierarchy lh WHERE lh.location = 'Arizona';