public void Test_FdbQueryTransformExpression()
        {
            var expr = FdbQueryExpressions.Transform(
                FdbQueryExpressions.RangeStartsWith(TuPack.EncodeKey("Hello", "World")),
                (kvp) => kvp.Value.ToUnicode()
                );

            Log(expr);

            Assert.That(expr, Is.Not.Null);
            Assert.That(expr.Source, Is.Not.Null.And.InstanceOf <FdbQueryRangeExpression>());
            Assert.That(expr.Transform, Is.Not.Null);

            Assert.That(expr.Type, Is.EqualTo(typeof(IAsyncEnumerable <string>)));
            Assert.That(expr.ElementType, Is.EqualTo(typeof(string)));

            Log(FdbQueryExpressions.ExplainSequence(expr));
        }
Exemplo n.º 2
0
        /// <summary>Projects each element of a sequence query into a new form.</summary>
        public static IFdbAsyncSequenceQueryable <R> Select <T, R>(this IFdbAsyncSequenceQueryable <T> query, Expression <Func <T, R> > selector)
        {
            if (query == null)
            {
                throw new ArgumentNullException(nameof(query));
            }
            if (selector == null)
            {
                throw new ArgumentNullException(nameof(selector));
            }

            var sourceExpr = query.Expression as FdbQuerySequenceExpression <T>;

            if (sourceExpr == null)
            {
                throw new ArgumentException("query");
            }

            var expr = FdbQueryExpressions.Transform(sourceExpr, selector);

            return(query.Provider.CreateSequenceQuery <R>(expr));
        }