/// <summary>
/// Checks if the given values are unique for the columns combination,
/// specified by <paramref name="getColumnsCombination"/>, in <paramref name="dbSet"/>.
/// </summary>
/// <param name="ruleBuilder"></param>
/// <param name="dbSet"></param>
/// <param name="getColumnsCombination">
/// Determines the columns combination.
/// By columns combination we mean object, containing multiple columns,
/// <para>e.g. <c>comment => new { comment.CommentId, comment.UserId }</c>.</para>
/// </param>
public static IRuleBuilderOptions <TObject, object[]> UniqueForColumnsCombinationInDbSet
<TObject, TColumnsCombination, TEntity>
(
this IRuleBuilder <TObject, object[]> ruleBuilder,
DbSet <TEntity> dbSet,
Expression <Func <TEntity, TColumnsCombination> > getColumnsCombination
)
where TObject : class
where TEntity : class
{
return(ruleBuilder
.MustAsync
(
(values, token) => EfCoreValidationHelpers.AreValuesUniqueForColumnsCombinationInDbSetAsync
(dbSet, getColumnsCombination, values, token)
)
.WithMessage("The given values are not unique for the specified columns combination"));
}