Following are some of the basic Linq command/samples for those who just want to start learning Linq. So this will help a lot to all the beginners to easily understand Linq queries.
// Basic Query
// To achieve Select * From ProductMst you need to write follofing linq Query
var Result1 = from p in db.ProductMst
select p;
// To achieve Select ProductID, ProductName, Price From ProductMst you need to write follofing linq Query
var Result2 = from p in db.ProductMst
select new {
p.ProductID,
p.ProductName,
p.Price
};
// Where Clause Query
// To achieve Select * From ProductMst Where ProductID = 1 you need to write follofing linq Query
var Result3 = from p in db.ProductMst
where p.ProductID == 1
select p;
// To achieve Select * From ProductMst Where SupplierId =2 and Price > 10 you need to write follofing linq Query
var Result4 = from p in db.ProductMst
where p.SupplierID == 2 && p.Price > 10
select p;
// To achieve Select * From ProductMst Where SupplierId =2 Or SupplierId=5 you need to write follofing linq Query
var Result5 = from p in db.ProductMst
where p.SupplierID == 2 || p.SupplierID == 5
select p;
// Order By Query
//To achieve Select * From ProductMst Order By ProductId you need to write follofing linq Query
var Result6 = from p in db.ProductMst
orderby p.ProductID
select p;
// To achieve Select * From ProductMst Order By ProductId Desc you need to write follofing linq Query
var Result7 = from p in db.ProductMst
orderby p.ProductID descending
select p;
// To achieve Select * From ProductMst Order By CategoryId, Price Desc you need to write follofing linq Query
var Result8 = from p in db.ProductMst
orderby p.CategoryID, p.Price descending
select p;
// Top Query
//To achieve Select Top 5 * From ProductMst you need to write follofing linq Query
var Result9 = (from p in db.ProductMst
select p).Take(5);
//To achieve Select Top 1 * From ProductMst you need to write follofing linq Query
var Result10 = (from p in db.ProductMst
select p).Take(1);
or
var Result11 = (from p in db.ProductMst
select p).First();
// Distinct Query
//To achieve Select Distinct CategoryId From ProductMst you need to write follofing linq Query
var Result13 = (from p in db.ProductMst
select p.CategoryID).Distinct();
// Group By Query
//To achieve Select CategoryId, Count(CategoryID) As FieldName From ProductMst Group By CategoryId you need to write follofing linq Query
var Result14 = from p in db.ProductMst
group p by p.CategoryID into g
select new {
CategoryId = g.Key,
FieldName = g.Count()
};
//To achieve Select CategoryId, Avg(UnitPrice) As NewField From ProductMst Group By CategoryId you need to write follofing linq Query
var Result15 = from p in db.ProductMst
group p by p.CategoryID into g
select new {
CategoryId = g.Key,
FieldName = g.Average(S => S.Price)
};
// Union Query
//To achieve Select * From ProductMst Where CategoryId =1 union Select * From ProductMst Where CategoryId = 2 you need to write follofing linq Query
var Result17 = (from p in db.ProductMst
where p.CategoryID == 1
select p).Union(
from m in db.ProductMst
where m.CategoryID == 2
select m
);