Composite indexes can be on simple types.  A query can be performed on an exact match or by partial matches of items inside. 

 

C# Example:

 

NinjaDbPro db = new NinjaDbPro("CompositeIndexExampleDir", "CompositeIndexExampleDir.db");

 

//Licensed Mode

//db.UserName = "John Smith 101224";

//db.LicenseKey = "aousdf832jasf==";

//Set before OpenDatabase. Default storage is IsolatedStorageDatabase. Other options are:

//db.Storage = new MemoryDatabase(); //In memory database

//db.Storage = new FileDatabase(); //Valid only for non Silverlight projects

 

//Open the database

db.OpenDatabase();

 

//Add a single property index if it doesn't already exist

if (!db.IndexExists<Person>("NameCreatedIndex"))

{

List<string> indexProperties = new List<string>();

indexProperties.Add("Name");

indexProperties.Add("DateCreated");

db.AddCompositeIndex<Person>("NameCreatedIndex", indexProperties,IndexStyle.NonUnique);

}

 

//Add a record to the database

Person person = new Person();

person.Name = "John Smith";

person.DateCreated = DateTime.Now;

db.Save(person);

 

//Build the index to find. This has to be in the same order as the index

List<object> indexValues = new List<object>();

indexValues.Add(person.Name);

indexValues.Add(person.DateCreated);

 

//Find an exact matach. If the index is unique, this is the fastest.

var exactQuery = db.CreateCompositeIndexQuery<Person>("NameCreatedIndex", indexValues);

 

//Lazy load the first record and write out a property

Console.WriteLine(exactQuery[0].LazyValue.DateCreated);

 

//Find a partial match

var partialQuery = db.CreateCompositeIndexQuery<Person>("NameCreatedIndex").Where(o => o.Indexes[0].ToString().StartsWith("John"));

 

//Write the DateCreated for all records that have a name beginning with John

foreach (var indexRecord in partialQuery)

{

Console.WriteLine(indexRecord.LazyValue.DateCreated);

}

 

//Close the database

db.CloseDatabase();