api-docs / org.ktorm.entity / eachMinByTo

eachMinByTo

inline fun <E : Any, T : BaseTable<E>, K : Any, C : Comparable<C>, M : MutableMap<in K?, in C?>> EntityGrouping<E, T, K>.eachMinByTo(
    destination: M,
    columnSelector: (T) -> ColumnDeclaring<C>
): M

(source code)

Group elements from the source sequence by key and get the min value of the columns or expressions provided by the
columnSelector function for elements in each group, then store the results in the destination map.

The key for each group is provided by the EntityGrouping.keySelector function, and the generated SQL is like:
select key, min(column) from source group by key.

Parameters

destination - a MutableMap used to store the results.

columnSelector - a function that accepts the source table and returns a column or expression.

Return
a destination map associating the key of each group with the min value in the group.