CODEWITHSUNDEEP
entity-frameworkentity-framework-ctp5
Ryan
Ryan

Reputation: 5546

Adding index to a table

I have a table Person: id, name

I often have queries like: 

select * from Person where name Like "%abc%".

I have 2 questions:

  1. How do I implement this query using code-first 5 (CTP5)
  2. How do I add an index on the name column to make data retrieval faster based on name like in the query?

Upvotes: 10

Views: 21250

Answers (2)

Sergey K
Sergey K

Reputation: 4114

in EF 6 you can create indexes like this

   Property(t => t.TotalValue)
            .HasColumnAnnotation(
                IndexAnnotation.AnnotationName,
                new IndexAnnotation(new IndexAttribute("IX_inventory_import_total_value", 1))
            );

Upvotes: 2

Ladislav Mrnka
Ladislav Mrnka

Reputation: 364259

Like operator can be performed with Contains function:

var query = from p in context.Persons
            where p.Name.Contains("abc")
            select p;

Index must be added by SQL - there is no special construction in EF to create index. You can execute this SQL from DB initialization.

First you must implement custom initializer:

public class MyInitializer : CreateDatabaseIfNotExists<MyContext>
{
  protected override void Seed(MyContext context)
  {
    context.Database.SqlCommand("CREATE INDEX IX_Person_Name ON Person (Name)");
  }
}

Then you must register new initializer:

DbDatabase.SetInitializer<MyContext>(new MyInitializer());

Upvotes: 24

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