CODEWITHSUNDEEP
c#linqlambda
Glory Raj
Glory Raj

Reputation: 17701

Linq with multiple foreach inserting items to table

I have list of ids like this below 

       List<int> ids = new List<int>();

and then i have list of lengths which is also integers like this below..

       List<int> lengths = new List<int>();

now i need to insert into table using linq query with the data format like this below

         ID  length
          1    1
          1    2
          1    3
          2    1
          2    2
          2    3

for that i am doing like this 

     foreach (var item in ids)
     {
             foreach (var item in lengths)
             {

              }

       }

With the above way i am not able insert the multiple id's in the table .. I am hoping there should be better way to do this.. Could any one please suggest any ideas on this one that would be very grateful to me..

Thanks in advance.

Upvotes: 0

Views: 771

Answers (2)

TheGeneral
TheGeneral

Reputation: 81533

If you wanted to project these 2 lists to a flattened list with LINQ, you could use SelectMany

Projects each element of a sequence to an IEnumerable and flattens the resulting sequences into one sequence.

// projecting to an anonymous type 

var results = ids.SelectMany(id => lengths.Select(length => new {id, length }));

// or projecting to a value tuple

var results = ids.SelectMany(id => lengths.Select(length => (id, length)));

Upvotes: 3

NetMage
NetMage

Reputation: 26926

If you really want a single loop, you can loop over the final result length and compute the indexes into each List:

var idsCount = ids.Count;
var lengthsCount = lengths.Count;
var totalCount = idsCount * lengthsCount;
for (int j1 = 0; j1 < totalCount; ++j1) {
    var id = ids[j1 / lengthsCount];
    var length = lengths[j1 % lengthsCount];
    new { id, length }.Dump();
    // insert id,length
}

Upvotes: 0

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