1.set student number ='2007 1' has no effect. Because the change condition is student number ='2007 1'

2. There is no comma between the three assignment clauses: student number ='2007 1', course number ='a 1', and grade ='98'.

3. Except for the character type (VARCHAR, nvarCHAR, char ...) fields, quotation marks are not allowed.

At least grades should not be based on character.

So, this statement is written like this:

Update grade setting course number ='a 1' grade =98, where student number ='2007 1'

The premise is that the grade is numerical, and the course number and student number are characters.