exposed-dao-r2dbc/org.jetbrains.exposed.v1.dao.r2dbc/EntityClass/optionalBackReferencedOn

optionalBackReferencedOn

infix fun <TargetID : Any, Target : Entity<TargetID>, REF> EntityClass<TargetID, Target>.optionalBackReferencedOn(column: Column<REF?>): OptionalBackReference<TargetID, Target, ID, Entity<ID>, REF>

Registers an optional reference as an immutable field of the parent entity class, which returns a child object of this EntityClass or null if no child references the parent entity.

The reference could have been defined on the child table in 1 of the following ways:

By the creation of a column using either optReference() or reference().nullable()
By the creation of a non-nullable reference() column where either 0 or 1 row(s) is expected in the relationship

@JvmName(name = "optionalBackReferencedOnNonNullable")

infix fun <TargetID : Any, Target : Entity<TargetID>, REF : Any> EntityClass<TargetID, Target>.optionalBackReferencedOn(column: Column<REF>): OptionalBackReference<TargetID, Target, ID, Entity<ID>, REF>

Registers an optional reference as an immutable field of the parent entity class, which returns a child object of this EntityClass or null if no child references the parent entity.

Overload of optionalBackReferencedOn for non-nullable reference columns — mirrors JDBC's overloaded optionalBackReferencedOn(Column<REF>).

infix fun <TargetID : Any, Target : Entity<TargetID>> EntityClass<TargetID, Target>.optionalBackReferencedOn(table: IdTable<*>): OptionalBackReference<TargetID, Target, ID, Entity<ID>, Any>

Registers an optional reference as an immutable field of the parent entity class, which returns a child object of this EntityClass or null if no child references the parent entity.

The reference should have been defined by the creation of a foreign key constraint on the child table, by using foreignKey().