How do I select distinct values in LINQ query?
You can make groups and get the first object from each group or you can use DistinctBy function to achieve the result.
- LINQ DistinctBy() on a Property.
- Using GroupBy and Select on a Property.
- LINQ Distinct() – By Field.
- LINQ GroupBy and Select Operators.
- Using Select and Distinct operators.
How do you select distinct by one column in LINQ?
“select distinct column in linq” Code Answer’s
- var uniquePeople = from p in people.
- group p by new {p. ID} //or group by new {p.ID, p.Name, p.Whatever}
- into mygroup.
- select mygroup. FirstOrDefault();
-
How does distinct work in Linq?
LINQ Distinct operator removes all the duplicate values from the collection and finally returns the dissimilar or unique values. The LINQ Distinct operator available in only Method Syntax and it not supports the Query Syntax. LINQ Distinct is an operator which comes under Set Operator.
What is distinct in Linq C#?
C# Linq Distinct() method removes the duplicate elements from a sequence (list) and returns the distinct elements from a single data source. It comes under the Set operators’ category in LINQ query operators, and the method works the same way as the DISTINCT directive in Structured Query Language (SQL).
How can I get distinct values of a column from Datatable in C# using Linq?
LINQ: Read Distinct Record from Data Table
- public JsonResult getEmpCity()
- {
- using (CompanyDBEntities dc = new CompanyDBEntities())
- {
- var query = (from p in dc. Emp_Information.
- select p. City). ToList();
- return new JsonResult.
- {
What collection would use an IEqualityComparer to enforce uniqueness?
The Distinct extension method returns a new collection of unique elements from the given collection. The Distinct extension method doesn’t compare values of complex type objects. You need to implement IEqualityComparer interface in order to compare the values of complex types.
How do I select distinct rows in C#?
Where: first parameter in ToTable() is a boolean which indicates whether you want distinct rows or not. second parameter in the ToTable() is the column name based on which we have to select distinct rows. Only these columns will be in the returned datatable.
How does SELECT distinct work?
The SELECT DISTINCT statement is used to return only distinct (different) values. Inside a table, a column often contains many duplicate values; and sometimes you only want to list the different (distinct) values.
Does SELECT distinct apply to all columns?
Yes, DISTINCT works on all combinations of column values for all columns in the SELECT clause.
What is the default equality Comparer C#?
By default, it will delegate to EqualityComparer. Default . This returns a comparer that can compare two objects of type T .
What is IEquatable in C#?
IEquatable.Equals(T) Method (System) Indicates whether the current object is equal to another object of the same type.