QueryStream Class Reference

Query stream interface. More...

Public Member Functions
virtual	~QueryStream ()
	Destructor.
virtual bool_t	Prepare (const ValueList &list)=0
	Prepares the stream before it is started. More...
virtual bool_t	Start (ResultSetList &list)=0
	Starts the stream. More...
virtual bool_t	Fetch (ValueList &list)=0
	Gets the next row and moves the iterator forward. More...

Protected Member Functions
	QueryStream ()
	Default constructor.

Detailed Description

Query stream interface.

A QueryStream is the interface between the application and the STREAM operator. When the operator starts inside a Query, the method is prepared with query-defined arguments. Then, if there are input operations, the STREAM operator builds the ResultSets and starts the iteration. Finally, the operator fetches rows until no more are available.

Application exceptions must be cached by the subclass that implements the interface.

Author

Sparsity Technologies http://www.sparsity-technologies.com

Member Function Documentation

virtual bool_t QueryStream::Fetch ( ValueList &  list )

pure virtual

Gets the next row and moves the iterator forward.

The end of sequence is denoted by returning TRUE with an empty row. A valid row must contain as many values (even NULL) as expected by the query.

Parameters

list	[out] Storage for the new rows

Returns

TRUE if there is a row or end of sequence, FALSE on error

virtual bool_t QueryStream::Prepare ( const ValueList &  list )

pure virtual

Prepares the stream before it is started.

Parameters

list	[in] Optional list of arguments

Returns

FALSE on error

virtual bool_t QueryStream::Start ( ResultSetList &  list )

pure virtual

Starts the stream.

Parameters

list	[in] Optional list of input ResultSets

Returns

FALSE on error

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The documentation for this class was generated from the following file:

• Query.h