Database

public final class Database

A Couchbase Lite database.

  • Initializes a Couchbase Lite database with a given name and database options. If the database does not yet exist, it will be created, unless the readOnly option is used.

    Throws

    An error when the database cannot be opened.

    Declaration

    Swift

    public init(name: String, config: DatabaseConfiguration = DatabaseConfiguration()) throws

    Parameters

    name

    The name of the database. May NOT contain capital letters!
    config

    The database options, or nil for the default options.

  • The database’s name.

    Declaration

    Swift

    public var name: String

  • The database’s path. If the database is closed or deleted, nil value will be returned.

    Declaration

    Swift

    public var path: String?

  • The total numbers of documents in the database.

    Declaration

    Swift

    public var count: UInt64

  • The database configuration.

    Declaration

    Swift

    public var config: DatabaseConfiguration

  • Gets a Document object with the given ID.

    Declaration

    Swift

    public func getDocument(_ id: String) -> Document?

  • Checks whether the document of the given ID exists in the database or not.

    Declaration

    Swift

    public func contains(_ docID: String) -> Bool

  • Gets document fragment object by the given document ID.

    Declaration

    Swift

    public subscript(id: String) -> DocumentFragment

  • Throws

    An error on a failure.

    Declaration

    Swift

    public func save(_ document: Document) throws

    Parameters

    document

    The document.

  • Deletes the given document. All properties are removed, and subsequent calls to the getDocument(id) method will return nil. Deletion adds a special tombstone revision to the database, as bookkeeping so that the change can be replicated to other databases. Thus, it does not free up all of the disk space occupied by the document.

    Throws

    An error on a failure.

    Declaration

    Swift

    public func delete(_ document: Document) throws

    Parameters

    document

    The document.

  • Purges the given document from the database. This is more drastic than deletion: it removes all traces of the document. The purge will NOT be replicated to other databases.

    Throws

    An error on a failure.

    Declaration

    Swift

    public func purge(_ document: Document) throws

    Parameters

    document

    The document.

  • Runs a group of database operations in a batch. Use this when performing bulk write operations like multiple inserts/updates; it saves the overhead of multiple database commits, greatly improving performance.

    Throws

    An error on a failure.

    Declaration

    Swift

    public func inBatch(_ block: () throws -> Void ) throws

    Parameters

    block

    The block to be executed as a batch operations.

  • Adds a database change listener block.

    Declaration

    Swift

    @discardableResult public func addChangeListener(_ block: @escaping (DatabaseChange) -> Void)
        -> NSObjectProtocol

    Parameters

    block

    The block to be executed when the change is received.

    Return Value

    An opaque object to act as the listener and for removing the listener when calling the removeChangeListener() method.

  • Adds a document change listener block for the given document ID.

    Declaration

    Swift

    public func addChangeListener(documentID: String,
                                  using block: @escaping (DocumentChange) -> Void) -> NSObjectProtocol

    Parameters

    documentID

    The document ID.
    block

    The block to be executed when the change is received.

    Return Value

    An opaque object to act as the listener and for removing the listener when calling the removeChangeListener() method.

  • Removes a change listener. The given change listener is the opaque object returned by the addChangeListener() method.

    Declaration

    Swift

    public func removeChangeListener(_ listener: NSObjectProtocol)

    Parameters

    listener

    The listener object to be removed.

  • Closes a database.

    Throws

    An error on a failure.

    Declaration

    Swift

    public func close() throws

  • Deletes a database.

    Throws

    An error on a failure.

    Declaration

    Swift

    public func delete() throws

  • Compacts the database file by deleting unused attachment files and vacuuming the SQLite database.

    Throws

    An error on a failure

    Declaration

    Swift

    public func compact() throws

  • Changes the database’s encryption key, or removes encryption if the new key is nil

    Throws

    An error on a failure

    Declaration

    Swift

    public func changeEncryptionKey(_ key: EncryptionKey?) throws

    Parameters

    key

    The encryption key in the form of an NSString (a password) or an NSData object exactly 32 bytes in length (a raw AES key.) If a string is given, it will be internally converted to a raw key using 64,000 rounds of PBKDF2 hashing. A nil value will decrypt the database.

  • Deletes a database of the given name in the given directory.

    Throws

    An error on a failure.

    Declaration

    Swift

    public class func delete(_ name: String, inDirectory directory: String? = nil) throws

    Parameters

    name

    The database name.
    directory

    The directory where the database is located at.

  • Checks whether a database of the given name exists in the given directory or not.

    Declaration

    Swift

    public class func exists(_ name: String, inDirectory directory: String? = nil) -> Bool

    Parameters

    name

    The database name.
    directory

    The directory where the database is located at.

    Return Value

    True if the database exists, otherwise false.

  • Creates a value index (type kValueIndex) on a given document property. This will speed up queries that test that property, at the expense of making database writes a little bit slower.

    Throws

    An error on failure.

    Declaration

    Swift

    public func createIndex(_ expressions: [Any]) throws

    Parameters

    expressions

    Expressions to index, typically key-paths. Can be Expression objects, NSExpression objects, or Strings that are expression format strings.

  • Creates an index on a given document property. This will speed up queries that test that property, at the expense of making database writes a little bit slower.

    Throws

    An error on failure.

    Declaration

    Swift

    public func createIndex(_ expressions: [Any], options: IndexOptions) throws

    Parameters

    expressions

    Expressions to index, typically key-paths. Can be Expression objects, NSExpression objects, or Strings that are expression format strings.
    options

    Options affecting the index, or NULL for default settings.

  • Deletes an existing index. Returns NO if the index did not exist.

    Throws

    An error on failure.

    Declaration

    Swift

    public func deleteIndex(_ expressions: [Any], type: IndexType) throws

    Parameters

    expressions

    Expressions indexed (same parameter given to -createIndexOn:.)
    type

    Type of index.

  • An iterator over all documents in the database, ordered by document ID.

    Declaration

    Swift

    public var allDocuments: DocumentIterator

  • Compiles a database query, from any of several input formats. Once compiled, the query can be run many times with different parameter values.

    Declaration

    Swift

    public func createQuery(where wherePredicate: Predicate? = nil,
                            groupBy: [PredicateExpression]? = nil,
                            having: Predicate? = nil,
                            returning: [PredicateExpression]? = nil,
                            distinct: Bool = false,
                            orderBy: [SortDescriptor]? = nil) -> PredicateQuery

    Parameters

    wherePredicate

    The where predicate.
    groupBy

    The group by expressions.
    having

    The having predicate.
    returning

    The returning values.
    distinct

    The distict flag.
    orderBy

    The order by as an array of the SortDescriptor object.

    Return Value

    The Predicate Query.