Save Short Associations

What is Short Association

A short association refers to only changing the association relationship between the current object and other objects, without further modifying the associated object.

For the UI interface:

• Reference association (one-to-one and many-to-one) is rendered as a radio menu

• Collection association (one-to-many and many-to-many) is rendered as a multiple select menu

For example:

Book Form

Name

Name

Edition

Edition

Price

Price

Store

O'REILLY

Authors

Authors

Eve Procello, Alex Banks

Authors

Define Input DTO

1. Install DTO language Intellij plugin: https://github.com/ClearPlume/jimmer-dto (This process is not required but highly recommended)

2. Create a new directory src/main/dto

3. Under src/main/dto, create a file Book.dto and write the following code:

   Book.dto

   input BookInputWithShortAssociations {
       #allScalars(this) 
       id(store) //default alias storeId  
       id(authors) as authorIds
   }

Generated Code

Java

BookInputWithShortAssociations.java

@GeneratedBy(
        file = "<yourproject>/src/main/dto/Book.dto"  
)
public class BookInputWithShortAssociations implements Input<Book> {  

    @Nullable
    private Long id;  

    @NotNull
    private String name;

    private int edition;

    @NotNull  
    private BigDecimal price;

    @Nullable
    private Long storeId;

    @NotNull
    private List<Long> authorIds;

    ...Omit other methods...  
}

Kotlin

BookInputWithShortAssociations.kt

@GeneratedBy(
        file = "<yourproject>/src/main/dto/Book.dto"
)  
data class BookInputWithShortAssociations(
    val id: Long?,
    val name: String,
    val edition: Int,
    val price: BigDecimal,
    val storeId: Long? 
    val authorIds: List<Long>  
) : Input<Book> {
    ...Omit other methods...   
}

Write HTTP Service

Java

BookController.java

@RestController
public class BookController {

    private final JSqlClient sqlClient;

    public BookController(JSqlClient sqlClient) {
        this.sqlClient = sqlClient; 
    }

    @PutMapping("/book")
    public int saveBookInputWithShortAssociations(
        @RequestBody BookInputWithShortAssociations input
    ) {
        return sqlClient
            .save(input)
            .getTotalAffectedRowCount();
    } 
} 

Kotlin

BookController.java

class BookController(  
    private val sqlClient: KSqlClient  
) {  

    @PutMapping("/book")
    fun saveBookInputWithShortAssociations( 
        @RequestBody input: BookInputWithShortAssociations
    ): Int =
        sqlClient
            .save(input)
            .totalAffectedRowCount
}

It can be seen that no matter how the Input DTO changes, Jimmer still only needs one method call to complete data saving.