Index

public struct Index: Indexer

Indexer implemenation to define a Database index used to query the database

Example:

   let index = Database.Index(name: "myView", version: "1.0", map: { (document, addRow) in
       if let type = document["type"] {
           addRow(type, nil)
       }
   })

   let config = Database.OpenDatabaseConfiguration(indexes: [index])

name
Declaration
Swift

public private(set) var name: String
version
Declaration
Swift

public private(set) var version: String

map

Declaration

Swift

public private(set) var map: Indexer.Map


                    
                    
                    reduce

Declaration

Swift

public private(set) var reduce: Indexer.Reduce?


                    
                    
                    init(name:version:map:reduce:)

Initialization of new Index

Important

Versioning:

Once created, a database index is stored as part of the data in database, for this reason, changes to an index require special handling.

If any part of the map function or reduce function change, the version string should be changed to ensure the index is properly updated. Failure to change this value when updating the code will lead to unpredicable results.

Example:

   let index = Database.Index(name: "myView", version: "1.0", map: { (document, addRow) in
       if let type = document["type"] {
           addRow(type, nil)
       }
   })

   let config = Database.OpenDatabaseConfiguration(indexes: [index])

Declaration

Swift

public init(name: String, version: String, map: @escaping Map, reduce: Reduce? = nil)

Parameters

`name`	Name of the index, required to run queries against the index.
`version`	Version of the index. See Versioning above
`map`	`Map` closure that defines the index. For further information see the `map` property.
`reduce`	Optional `Reduce` closure that performs summarization during queries. For further information see the `reduce` property.