Find One By

Definition

The findOneBy method allows you to get one record of a table filtered by the conditions that are supplied.

caution

If the constructed query returns 0 or more than one record, this method will return a null KRow.

Available methods

• findOneBy(KFindFunction<KFrom, KQuery> kFindFunction, KColumnAllowedToSelect... selects): Receives a KFindFunction that allows adding conditions to the base query and a variable quantity of columns and values that will be added to the SELECT list. Among the possible values are: KTableColumn, KColumn, Values, KCondition, Columns with over, Columns with alias, KRaw, Case conditional expression.
• findOneBy(String jdbc, KFindFunction<KFrom, KQuery> kFindFunction, KColumnAllowedToSelect... selects): Receives the name of datasource connection to which you need to connect, a KFindFunction that allows adding conditions to the base query and a variable quantity of columns and values that will be added to the SELECT list. Among the possible values are: KTableColumn, KColumn, Values, KCondition, Columns with over, Columns with alias, KRaw, Case conditional expression.

Example: KFindFunction, KColumnAllowedToSelect...

Java code:

final Language language =
    languageRepository.findOneBy(
        (KFrom kFrom) -> 
            kFrom
            .where(LANGUAGE.ID.eq(7L)),
        LANGUAGE.ID,
        LANGUAGE.NAME
    );

SQL generated:

SELECT la.id, la.name
FROM language la
WHERE la.id = ?1

Parameters:

• ?1: 7

Example: String, KFindFunction, KColumnAllowedToSelect...

Java code:

final Language language =
    languageRepository.findOneBy(
        K.JDBC_LEGACY,
        (KFrom kFrom) -> 
            kFrom
            .where(LANGUAGE.ID.eq(7L)),
        LANGUAGE.ID,
        LANGUAGE.NAME
    );

SQL generated:

SELECT la.id, la.name
FROM language la
WHERE la.id = ?1

Parameters:

• ?1: 7