Please write a stored function named fHW$\_7\_$xxxx$()$ which will take two inputs $($type$,$ keyword$).$

a$.$ The keyword is a substring used to search the course name. You must use LIKE for the pattern match.

b$.$ If the type is not $1$ or $2,$ return an error message $$Please input a valid type.$$

c$.$ If the keyword is empty or null, return an error message $$Please input a valid keyword.$$

d$.$ If there is no course name contains the keyword, return $$No course found that contains keyword: zzz$.$ where zzz

is the input keyword.

e$.$ If type is $1,$ return all course ID: course name that course name contains the keyword.

f$.$ If type is $2,$ return all course ID: student ID who took the courses that course name contains the keyword.

g$.$ The return should be in one line and your report format must match the test cases.

h$.$ You need to use group$\_$concat$()$ function to merge multiple rows output into one line.

i$.$ Please refer to Students, Courses, Students$\_$Courses tables in the dreamhome database.