mysql - do not return row when value in NULL

Question

When trying to select everything except when question_type!= 'A'; The row do not return data when question_type is NULL.

select * from table where question_type!= 'A';

Gordon Linoff · Accepted Answer · 2016-06-23 08:20:45Z

4

So, include that in the where clause;

select t.*
from table t
where question_type <> 'A' or question_type is null;

Or, use the "null-safe" equal:

select t.*
from table t
where not question_type <=> 'A' ;

ANSI SQL implements IS DISTINCT FROM and IS NOT DISTINCT FROM. The <=> operator is equivalent to IS NOT DISTINCT FROM.

answered Jun 23, 2016 at 8:20

Gordon Linoff

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1 Comment

The null-safe equal rocks!

James Jithin · Accepted Answer · 2016-06-23 08:24:09Z

1

Return a value in case of null and go ahead:

select * from table where COALESCE(question_type, '') <> 'A';

answered Jun 23, 2016 at 8:24

James Jithin

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