The Queries in this page solved at the library database. It is a sample database generated by randomly records. You can download it from the link. You will see more than 500 examples in the future. You can filter from the search panel above by selecting sql statements. I hope you will like it

SQL Distinct Where Examples


Solution 1)

Select count(distinct authorId) from students 
join borrows on students.studentId = borrows.studentId 
join books on books.bookId = borrows.bookId 
where = 'Ida' and students.surname = 'Gray'


Select - Distinct - Join - Where - Multi Condition - Aggragate - Çoklu Tablo -
Library Database