Write Sql queries for Oracle database

1. display schema_name,table_name,schema_details logic for schema_details if owner is sys, then schema_details should be "Owner is Sys" if owner is HR, then schema_details should be "Owner is HR" for all others it should display "Others"

use decode and case.

2. get total no of columns in the database which have datatype VARCHAR2

3. Find all columns which have datatype number and is present in HR schema and column name starts with CU

4. Find all constraints present in employees table in HR schema

5. What is the difference betwwen case and decode