根据多个联接条件从两个自定义列表中选择项目

Question

I have to custom data lists:

    public class DatType1
{

    public string yr;
    public string qr;
    public string mt;
    public string cw;
    public string tar;
    public string rg;
    public string mac;
    public string fuel;
    public double fp;
    public double fi;
    public double fd;

}

and

public class DatType2
{

    public string yr;
    public string qr;
    public string mt;
    public string cw;
    public string tar;
    public string RG;
    public double pp;
    public double pi;
    public double fp;
    public double fi;
    public double fd;


}

As you can see there is a lot of overlap between the two. I would like to add the values for DatType1.fp, DatType1.fi, DatType1.fd to DateType2 but I need to put them in the right place, the right place means where a bunch of the items are equal.

I have looked a lot on the site here but couldnt figure it out. I have tried sth like this:

from a in TableA
from b in TableB
where a.yr==b.yr & a.qr==b.qr & a.RG == b.RG & a.tar ==b.tar
select( r=> new DatType2{....}

and then in the brackets repeat everything from DateType2 that I want to keep and add DatType1.fp, DatType1.fi, DatType1.fd.

If I did this with brute force I would do a double for loop and go through each line of DatType1 and see where I match a row in DatType2 and then add DatType1.fp, DatType1.fi, DatType1.fd - But this would be very slow

This however didnt work and is far from elegant! ...:) Any pointers would be much appreciated.

Thanks

Answer 1

I would create a base class, with all the common data:

public class BaseClass    
{
    public string yr;
    public string qr;
    public string mt;
    public string cw;
    public string tar;
    public string rg;
    public double fp;
    public double fi;
    public double fd;

    public void SetAllValues(BaseClass Other)
    {
        this.yr = Other.yr;
        this.qr = Other.qr;
        //til the end.
        this.fd = Other.fd;
    }

    //with this you check the equal stuff...
    public bool HasSameSignature(BaseClass Other)
    { 
        if (this.yr != Other.yr) return false;
        if (this.qr != Other.qr) return false;  
        //all other comparisons needed
        return true;
    }

    //with this you set the desired ones:
    public void SetDesired(BaseClass Other)
    {
        this.fp = Other.fp;
        this.fi = Other.fi;
        //all other settings needed
    }
}    

And the others would inherit this base:

public class DatType1 : BaseClass
{
    public string mac;
    public string fuel;
}


public class DatType2 : BaseClass
{
    public double pp;
    public double pi;
}

Now you can use the a.HasSameSignature(b) instead of a.yr==b.yr & a.qr==b.qr & a.RG == b.RG & a.tar ==b.tar . And Set the values (or create a copy method, as you wish)....

Answer 2

I would recommend overloading the equality comparison of the two objects to make the DatType1:IEquatable<DatType2> and/or DatType2:IEquatable<DatType1> . That would allow you to use dat1.Equals(dat2) or dat2.Equals(dat1) .

Alternatively, you can implement a comparison delegate and pass that in as dat1.Equals(dat2,comparer) or comparer.Compare(dat1,dat2) . The later is probably ideal if you don't have control over the DatType1 or DatType2 types.