Update README.md

Author: AnghelLeonard

README.md

@@ -2711,4 +2711,13 @@ Calling `fetchWithBooksByGenre()` works fine only that the following warning is
 
 **Key points:**\
      - strive for smallest data types (e.g., for `EnumType.ORDINAL` set `@Column(columnDefinition = "SMALLINT")`)
-     
+
+----------------------------------------------------------------------------------------------------------------------
+
+192. **[How To Map Java `enum` To Database Via `AttributeConverter`](https://github.com/AnghelLeonard/Hibernate-SpringBoot/tree/master/HibernateSpringBootEnumAttributeConverter)**
+ 
+**Description:** This application maps a Java `enum` via `AttributeConverter`. In other words, it maps the `enum` values `HORROR`, `ANTHOLOGY` and `HISTORY` to the integers `1`, `2` and `3` and viceversa. This allows us to set the column type as `SMALLINT` which is less space-consuming than `VARCHAR(9)` needed in this case.
+
+**Key points:**\
+     - define a custom `AttributeConverter`\
+     - annotate with `@Converter` the corresponding entity field