Truncated incorrect INTEGER value

  
substring_index(substring_index(
  r.description, 'Grade ', -1), ' ', 1)

1
12

2
17


  
substring_index(substring_index(
        r.description, 'Grade ', -1), ' ', 1)
CONVERT(SUBSTRING_INDEX(SUBSTRING_INDEX(
        r.description, 'Grade ',-1),' ',1),UNSIGNED)
id
grade_id
description

1
12
12
1
1
Foo Grade 12 Bar

2
17
17
2
2
Foo Grade 17 Bar

3

0
3
3
Foo Grade 12 Grade 

4
MyCO
0
4
4
Foo Grade 12 Grade MyCO