Query By Example (QBE)

Author: AnghelLeonard

HibernateSpringBootExampleApi/README.md

@@ -1,10 +1,11 @@
 **[How To Check If A Transient Entity Exists In The Database Via Spring Query By Example (QBE)](https://github.com/AnghelLeonard/Hibernate-SpringBoot/tree/master/HibernateSpringBootExampleApi)**
 
-**Description:** This application is an example of using Spring Data Query By Example (QBE) to check if a transient entity exists in the database. Consider the `Book` entity and a Spring controller that exposes an endpoint as: `public String checkBook(@Validated @ModelAttribute Book book, ...)`. Beside writting an explicit JPQL, we can rely on Spring Data Query Builder mechanism or, even better, on Query By Example (QBE) API. This is quite useful if the entity has a significant number of attributes and:
+**Description:** This application is an example of using Spring Data Query By Example (QBE) to check if a transient entity exists in the database. Consider the `Book` entity and a Spring controller that exposes an endpoint as: `public String checkBook(@Validated @ModelAttribute Book book, ...)`. Beside writting an explicit JPQL, we can rely on Spring Data Query Builder mechanism or, even better, on Query By Example (QBE) API. This API is quite useful if the entity has a significant number of attributes and:
 
-- we need a head-to-head comparison of each attribute value to the corresponding column value
-- we consider that a `Book` exists if at least one attribute value matches a column value
-- we want to compare only a subset of attributes
+- for all attributes, we need a head-to-head comparison of each attribute value to the corresponding column value
+- for a subset of attributes, we need a head-to-head comparison of each attribute value to the corresponding column value
+- for a subset of attributes, we return true at first match between an attribute value and the corresponding column value
+- any other scenario
 
 **Key points:**
 - the repository, `BookRepository` extends `QueryByExampleExecutor`