TableViz raise Unexpected error when table include null value

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when table include number type columns and the value is null , The TableViz cannot display this table when these columns be selected in NOT GROUPED BY

Superset version

0.26.3 On centos7 + Python 3.6.5

Expected results

Actual results

Unexpected error.

Steps to reproduce

Table DDL: CREATE TABLE testt ( id int(11) NOT NULL AUTO_INCREMENT, name varchar(255) DEFAULT NULL, value int(255) DEFAULT NULL, PRIMARY KEY (id) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8; Data:

id	name	value
1	aaa	1
2	bbb
3	ccc	3
4	ddd

And choose these three columns in TableViz’s NOT GROUPED BY selector.

[Wujiao233]

the master is ok…but i think it’s not a good idea to fill number type null to 0 .In some case null is not mean 0 .

[villebro]

This is a duplicate of #5353