CommandFactories¶

CommandFactories is a DdlCommandFactory.

Creating Instance¶

CommandFactories takes the following to be created:

• ServiceContext
• MetaStore

CommandFactories is created alongside EngineContext

Creating DdlCommand¶

create is part of the DdlCommandFactory abstraction.

create creates a DdlCommand for a DdlStatement or a KsqlStructuredDataOutputNode.

DdlStatement¶

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

create looks up (the class of) the given DdlStatement (in FACTORIES) 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.

FACTORIES¶

CommandFactories creates FACTORIES lookup table (of handlers) to create DdlCommands from DdlStatements.

handleAlterSource¶

AlterSourceCommand handleAlterSource(
  AlterSource statement)

handleAlterSource requests the AlterSourceFactory for an AlterSourceCommand (for the given AlterSource statement).

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).