CommandFactories¶

CommandFactories is a DdlCommandFactory.

Creating Instance¶

CommandFactories takes the following to be created:

• ServiceContext
• MetaStore

CommandFactories is created alongside an EngineContext

Command Factories¶

CommandFactories creates FACTORIES collection of handlers (functions) for DdlStatements to produce DdlCommands.

The FACTORIES is used in create.

Creating DdlCommand¶

create is part of the DdlCommandFactory abstraction.

DdlStatement¶

DdlCommand create(
  String sqlExpression,
  DdlStatement ddlStatement,
  SessionConfig config)

create looks up (the class of) the given DdlStatement in the FACTORIES registry to handle it (and produce a DdlCommand).

Unless found, create throws a KsqlException:

Unable to find ddl command factory for statement: [class] valid statements:[FACTORIES]

KsqlStructuredDataOutputNode¶

DdlCommand create(
  KsqlStructuredDataOutputNode outputNode)

For a KSTREAM node output type (of the given KsqlStructuredDataOutputNode), create requests the CreateSourceFactory for a CreateStreamCommand.

Otherwise, create requests the CreateSourceFactory for a CreateTableCommand.

handleCreateStream¶

CreateStreamCommand handleCreateStream(
  CallInfo callInfo,
  CreateStream statement)

handleCreateStream requests the CreateSourceFactory for a CreateStreamCommand (for the given CreateStream statement).

handleCreateTable¶

CreateTableCommand handleCreateTable(
  CallInfo callInfo,
  CreateTable statement)

handleCreateTable requests the CreateSourceFactory for a CreateTableCommand (for the given CreateTable statement).