public static TSource FirstOrDefault <TSource>(this ReadOnlyMemory <TSource> source)
{
var aggregate = new FirstOrDefault <TSource>();
MemoryNode.ProcessMemory(source, ref aggregate);
return(aggregate.GetResult());
}
public static TSource FirstOrDefault <TSource>(this List <TSource> source)
{
var aggregate = new FirstOrDefault <TSource>();
ListSegmentNode.ProcessList(source, ref aggregate);
return(aggregate.GetResult());
}
public static TSource FirstOrDefault <TSource>(this TSource[] source)
{
var aggregate = new FirstOrDefault <TSource>();
ArrayNode.ProcessArray(source, ref aggregate);
return(aggregate.GetResult());
}
public static object GetColumnById(this object dbContext, string tableName, string columnName, object id)
{
var table = (IQueryable)dbContext.GetType().GetProperty(tableName).GetValue(dbContext);
var row = Expression.Parameter(table.ElementType, "row");
var filter = Expression.Lambda(Expression.Equal(Expression.Property(row, "Id"), Expression.Constant(id)), row);
var column = Expression.Property(row, columnName);
var selector = Expression.Lambda(column, row);
var query = Call(Where.MakeGenericMethod(row.Type), table, filter);
query = Call(Select.MakeGenericMethod(row.Type, column.Type), query, selector);
var value = Call(FirstOrDefault.MakeGenericMethod(column.Type), query);
return(value);
}
public void FirstOrDefaultTestNegative()
{
Assert.AreEqual(FirstOrDefault.FirstOrDefaultForLoop(People.PeopleList, "George")?.FirstName, FirstOrDefault.FirstOrDefaultLinq(People.PeopleList, "George")?.FirstName);
}
public void FirstOrDefaultTestPositive()
{
Assert.AreEqual(FirstOrDefault.FirstOrDefaultForLoop(People.PeopleList, "Dan")?.FirstName, FirstOrDefault.FirstOrDefaultLinq(People.PeopleList, "Dan")?.FirstName);
}
public void ShowExample_Click(object sender, EventArgs e)
{
Form form = null;
switch (((Button)sender).Name)
{
// LINQ Dynamic | Restriction Operators
case "uiROWhere":
form = new Where();
break;
// LINQ Dynamic | Projection Operators
case "uiPOSelect":
form = new Select();
break;
case "uiPOSelectMany":
form = new SelectMany();
break;
// LINQ Dynamic | Aggregate Operators
case "uiAOMin":
form = new Min();
break;
case "uiAOMax":
form = new Max();
break;
case "uiAOSum":
form = new Sum();
break;
case "uiAOCount":
form = new Count();
break;
case "uiAOAverage":
form = new Average();
break;
case "uiAOAggregate":
form = new Aggregate();
break;
// LINQ Dynamic | Query Execution
case "uiQEDeferredExecution":
form = new DeferredExecution();
break;
case "uiQEQueryReuse":
form = new QueryReuse();
break;
case "uiQEImmediateExecution":
form = new ImmediateExecution();
break;
// LINQ Dynamic | Join Operators
case "uiJOCrossJoin":
form = new CrossJoin();
break;
case "uiJOGroupJoin":
form = new GroupJoin();
break;
case "uiJOCrossWithGroupJoin":
form = new CrossJoinwithGroupJoin();
break;
case "uiJOLeftOuterJoin":
form = new LeftOuterJoin();
break;
// LINQ Dynamic | Set Operators
case "uiSODistinct":
form = new Distinct();
break;
case "uiSOExcept":
form = new Except();
break;
case "uiSOIntersect":
form = new Intersect();
break;
case "uiSOUnion":
form = new Union();
break;
// LINQ Dynamic | Element Operators
case "uiEOElementAt":
form = new ElementAt();
break;
case "uiEOFirst":
form = new First();
break;
case "uiEOFirstDefault":
form = new FirstOrDefault();
break;
// LINQ Dynamic | Custom Sequence Operators
case "uiCSOCombine":
form = new Combine();
break;
// LINQ Dynamic | Quantifiers
case "uiQuantifiersAll":
form = new All();
break;
case "uiQuantifiersAny":
form = new Any();
break;
// LINQ Dynamic | Grouping Operators
case "uiGOGroupBy":
form = new GroupBy();
break;
// LINQ Dynamic | Miscellaneous Operators
case "uiMOConcat":
form = new Concat();
break;
case "uiMOEqualAll":
form = new EqualAll();
break;
// LINQ Dynamic | Generation Operators
case "uiGORepeat":
form = new Repeat();
break;
case "uiGORange":
form = new Range();
break;
// LINQ Dynamic | Ordering Operators
case "uiOOOrderBy":
form = new OrderBy();
break;
case "uiOOThenBy":
form = new ThenBy();
break;
case "uiOOThenByDescending":
form = new ThenByDescending();
break;
case "uiOOOrderByDescending":
form = new OrderByDescending();
break;
case "uiOOReverse":
form = new Reverse();
break;
// LINQ Dynamic | Conversion Operators
case "uiCOOfType":
form = new OfType();
break;
case "uiCOToArray":
form = new ToArray();
break;
case "uiCOToDictionary":
form = new ToDictionary();
break;
case "uiCOToList":
form = new ToList();
break;
// LINQ Dynamic | Partitioning Operators
case "uiPOTake":
form = new Take();
break;
case "uiPOTakeWhile":
form = new TakeWhile();
break;
case "uiPOSkip":
form = new Skip();
break;
case "uiPOSkipWhile":
form = new SkipWhile();
break;
}
form.StartPosition = FormStartPosition.CenterParent;
form.ShowDialog();
}
