c# - comparant répertorie sous plusieurs conditions - Stack Overflow

public class ConsumableThreshold
{
    public int ThresholdType { get; set; }
    public int ManufacturerID { get; set; }
    public int ModelID { get; set; }
    public int ConsumableVariantID { get; set; }
}

I'm attempting to check two lists of objects for shared properties. I will need to check various other properties depending on the results of previous matches.

For example if the ThresholdType matches, I then need to check a second property and if that matches I need to check the ModelID.

I have this query, which effectively does what I want but there are problems with it mainly that further down I drill the more the readability is going to be reduced.

var query= existingThresholds.Where(
    e => defaultThresholds.Any(
        d => d.ThresholdType == e.ThresholdType)).Where(
             e => defaultThresholds.Any(
                d => d.ManufacturerID == e.ManufacturerID)).ToList();

I wanted to do this using join but it does not support the && operator.

var query2 = from e in existingThresholds
             join d in defaultThresholdson 
             e.ThresholdType equals d.ThresholdType &&
             e.ManufacturerID equals d.ManufacturerID
             select e;

Is there a way to write this as a query without chaining .Where() conditions?

Sure - you're just trying to join on a compound key, which is usually accomplished with an anonymous type:

var query2 = from e in existingThresholds
             join d in defaultThresholdson 
             on new { e.ThresholdType, e.ManufacturerID } equals 
                new { d.ThresholdType, d.ManufacturerID }
             select e;

(It's slightly odd to ignore one half of the join later on, admittedly...)

Is there a way to write this as a query without chaining .Where() conditions?

Yes, use an anonymous type, which has a built-in equality check that compares the values of all properties by name:

var query2 = from e in existingThresholds
             join d in defaultThresholds
             on       new { e.ThresholdType , e.ManufacturerID }
               equals new { d.ThresholdType , d.ManufacturerID }
             select e;

public class ConsumableThreshold
{
    public int ThresholdType { get; set; }
    public int ManufacturerID { get; set; }
    public int ModelID { get; set; }
    public int ConsumableVariantID { get; set; }
}

I'm attempting to check two lists of objects for shared properties. I will need to check various other properties depending on the results of previous matches.

For example if the ThresholdType matches, I then need to check a second property and if that matches I need to check the ModelID.

I have this query, which effectively does what I want but there are problems with it mainly that further down I drill the more the readability is going to be reduced.

var query= existingThresholds.Where(
    e => defaultThresholds.Any(
        d => d.ThresholdType == e.ThresholdType)).Where(
             e => defaultThresholds.Any(
                d => d.ManufacturerID == e.ManufacturerID)).ToList();

I wanted to do this using join but it does not support the && operator.

var query2 = from e in existingThresholds
             join d in defaultThresholdson 
             e.ThresholdType equals d.ThresholdType &&
             e.ManufacturerID equals d.ManufacturerID
             select e;

Is there a way to write this as a query without chaining .Where() conditions?

Sure - you're just trying to join on a compound key, which is usually accomplished with an anonymous type:

var query2 = from e in existingThresholds
             join d in defaultThresholdson 
             on new { e.ThresholdType, e.ManufacturerID } equals 
                new { d.ThresholdType, d.ManufacturerID }
             select e;

(It's slightly odd to ignore one half of the join later on, admittedly...)

Is there a way to write this as a query without chaining .Where() conditions?

Yes, use an anonymous type, which has a built-in equality check that compares the values of all properties by name:

var query2 = from e in existingThresholds
             join d in defaultThresholds
             on       new { e.ThresholdType , e.ManufacturerID }
               equals new { d.ThresholdType , d.ManufacturerID }
             select e;

Source