如下, linq语句的group by中包含Year/Month时会抛例外,BegDate在c#中的类型为Datetime, 在数据库中为 timestamp without time zone. group q by new { q.LineSeq, YearMonth = new { Year = q.BegDate.Year, Month = q.BegDate.Month } }; 例外: System.ArgumentException
public class Model { public double Time { get; set; } public double Distance { get; set; } [InjectLambda] public double Velocity => Distance / Time; public static Expression<Func<Model, double>> VelocityExpr => v => v.Distance / v.Time; } Again, instead of placing [InjectLambda] ...
Add Text to a Textbox without removing previous text Add Two Large Numbers Using Strings - Without Use of BigInt Add user properties settings at run time... Add Username and Password Json File in C# Add XElement to XDocument Add...
Extension methods, which enable you to extend an existing type with your own methods without modifying the type itself.For details, see Visual Basic Features That Support LINQ.Deferred and immediate query executionQuery execution is separate from creating a query. After a query is created, its exe...
selecting distinct values without case sensitive selecting records given with a array using Linq Selecting top 5 rows from a datatable Self Join using EF and lambda expression Self referencing foreign keys in EF Code First Set Command timeout in NHibernate Setting DataTable fields to null Shares ...
Without folding as shown in figure 1 below is inherently harder to read then in figure 2. Consider writing figure 1 today then need to modify figure 1 six or more months down the road verses the code in figure 2. Figure 1 Copy
Instead of adding data to a chart series one point at a time, you can use a DataBindXY method on the chart's DataPointCollection to insert a sequence of data points without using a loop. You can see this happen in the DelaysByDayChartBuilder, which calculates the total of all delays (...
from evDateTime in eventMetadata.Attributes() where evDateTime.Name.LocalName == "start-date-time"select evDateTime;return (dateTimeResult.Count() > 0) ? dateTimeResult.First().Value : null;}Retrieve the Teams:protected String[] GetTeams(XElement sportsEvent){...
We never bothered to call guest services, one, because we shouldn’t have to get ahold of someone to turn over our room and two, by the time we returned to the hotel at night, it was way too late and didn’t want to sit outside of our room whi...
the default value for each property isnull. Being a good DBA, I never (without good reason) havenulls lying around my databases, so my tables always have default values assigned to each column. When the LINQ objects however are sent back to the database, the operation fails since the DB...