Question

I have a column

StudentData (varchar)

Sample values:

Not regular
90
15.2
55
4
0
>15
regular
35

I have a condition to find out all the students which have StudentData value greater than 10
or have a NULL value.

When I try to convert it fails saying conversion fails. How can get those values? I am expecting a resultset something like

studentdata
90
15.2
55

35

Please advice.

Answer 1

I think you’re looking for this:

select * from t
where studentdata is null or 
  (isnumeric(studentdata) = 1 and CAST(studentdata AS float) > 10)

Anyway, you should consider storing appropriate information in that column, instead of a mix of things.

Let me know if you have any issue with it.