Hiberate search for child entities

Question

I have three classes defined as:

1)Category class:-

@Entity
@Table(name = "CATEGORY")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Indexed
public class Category {

@Id
@GeneratedValue
private Long id;

@Field(index = Index.YES, store = Store.YES, analyzer = @Analyzer(definition = "ngram"))
private String categoryName;

@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "categoryId", referencedColumnName = "id")
@LazyCollection(LazyCollectionOption.TRUE)
@IndexedEmbedded
private List<SubCategory> subCategories;

private Long creationTime;

private Long updationTime;
}

2) SubCategory class:-

 @Entity
 @Table(name = "SUB_CATEGORY")
 @Data
 @NoArgsConstructor
 @AllArgsConstructor
 @Indexed
 public class SubCategory {


@Id
@GeneratedValue
private Long id;

@Field(index = Index.YES,store = Store.YES,analyzer = @Analyzer(definition = "ngram1"))
private String subCategoryName;

@Field(index = Index.YES,store = Store.YES)
private Long categoryId;

@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "subCategoryId", referencedColumnName = "id")
@LazyCollection(LazyCollectionOption.TRUE)
@IndexedEmbedded
private List<Pages> pages;

private Long creationTime;
}

3) Pages class:-

 @Entity
 @Table(name = "PAGES")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Indexed
public class Pages {

@Id
@GeneratedValue
private Long id;

@Field(index = Index.YES,store = Store.YES,analyzer = @Analyzer(definition = "ngram2"))
private String pageName;

@Field(index = Index.YES,store = Store.YES,analyzer = @Analyzer(definition = "ngram2"))
private String pageDescription;

@Field(index = Index.YES,store = Store.YES,analyzer = @Analyzer(definition = "ngram2"))
private Long subCategoryId;

private Long creationTime;
}

Now the data is defined like:-

   Category              SubCategory              Pages
   --------              ------------             -------
   Vehicle                Car                     BMW
   Electricals            MotorCycle              Hero
   ...........            ........                Audi
   ...........            ........                ...... 
   Lapzz                  Laptop                  ......
                                                  Dell

Now I am stuck at getting the query that will search in all three classes using hibernate search(i.e.-If I search Lap*) I should get result from Categories,Subcategories and Pages and only the rows matching the query only not the complete object of Category.

eg-I should get in the result set the row containing Lapzz in categories and row containing Laptop in subcategories when I search for Lap*. Please help my find this solution.

What do you mean when you say "row"? In your results, do you want a mix of `Category`, `SubCategory` and `Pages` objects, depending on what matched? Or do you want exclusively `Page` objects, even when your crtieria matched a category (in which case you'd get all the pages of the matching category)? — yrodiere, Jul 02 '18 at 15:05
I want mix of Category, Subcategy and Pages.Suppose I search for a query then the result should contain mixture of all three table data. — Ayush Srivastava, Jul 03 '18 at 15:56

yrodiere · Accepted Answer · 2018-07-04T08:22:28.680

This should do what you want, as far as I understand:

String searchTerms = ...;

QueryBuilder categoryQb = fullTextEntityManager.getSearchFactory().buildQueryBuilder().forEntity( Category.class ).get();
QueryBuilder subCategoryQb = fullTextEntityManager.getSearchFactory().buildQueryBuilder().forEntity( SubCategory.class ).get();
QueryBuilder pagesQb = fullTextEntityManager.getSearchFactory().buildQueryBuilder().forEntity( Pages.class ).get();

Query categoryQuery = categoryQb.keyword()
    .onField( "categoryName" )
    .matching( searchTerms )
    .createQuery();
Query subCategoryQuery = subCategoryQb.keyword()
    .onField( "subCategoryName" )
    .matching( searchTerms )
    .createQuery();
Query pagesQuery = pagesQb.keyword()
    .onFields(
        "pageName",
        "pageDescription"
    )
    .matching( searchTerms )
    .createQuery();

Query luceneQuery = categoryQb.bool()
        .should( categoryQuery )
        .should( subCategoryQuery )
        .should( pagesQuery )
        .createQuery();

FullTextQuery fullTextQuery = fullTextEntityManager.createFullTextQuery(
    luceneQuery,
    Category.class, SubCategory.class, Pages.class
);

List<?> results = fullTextQuery.getResultList();

Several warnings are necessary here:

since you are using ngram filters, you may need to use a different analyzer when querying; see this answer
your @Field annotation on Pages.subcategoryId is highly suspicious: it doesn't make sense to analyze a numeric value. For that matter, it's suspicious to store the ID of another entity in Pages, you'd generally want to have a field whose type is SubCategory instead and annotate it with @ManyToOne.
if you want your query to match a category that doesn't have the search terms in its description, but contains a page whose name or description contains the search terms, you will have to add an IndexedEmbedded and add the embedded fields ("pages.pageName", "pages.pageDescription", ...) to your search queries.

Thanks for the answer.I will incorporate all these changes. – Ayush Srivastava Jul 04 '18 at 10:26 — Ayush Srivastava, Jul 04 '18 at 10:26

Hiberate search for child entities

1 Answers1