MySQL queries all records with no repeated fields _ MySQL

MySQL queries all records of a field that are not repeated bitsCN.com. assume that there are now N records that indicate
Id author title
1 aaa AAA
2 bbb BBB
3 ccc
4 ddd
5 eee AAA
Now I want to query all records with no duplicate titles from these five records.
Select distinct title, author from book is not allowed because distinct can only act on one field
Ask how to write
Answer:

Select a. * from book a right join (
Select max (id) id from book group by title) B on B. id = a. id
Where a. id is not null

If the first matching record is selected, use min (id ).


Select a. * from book a right join (
Select min (id) id from book group by title) B on B. id = a. id
Where a. id is not null
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