You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

155 lines
4.4 KiB
C++

/*=========================================================================
Program: Visualization Toolkit
Module: vtkRowQuery.h
Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
All rights reserved.
See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notice for more information.
=========================================================================*/
/*-------------------------------------------------------------------------
Copyright 2008 Sandia Corporation.
Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
the U.S. Government retains certain rights in this software.
-------------------------------------------------------------------------*/
/**
* @class vtkRowQuery
* @brief abstract interface for queries that return
* row-oriented results.
*
*
* The abstract superclass of query classes that return row-oriented (table)
* results. A subclass will provide database-specific query parameters and
* implement the vtkRowQuery API to return query results:
*
* Execute() - Execute the query. No results need to be retrieved at this
* point, unless you are performing caching.
*
* GetNumberOfFields() - After Execute() is performed, returns the number
* of fields in the query results.
*
* GetFieldName() - The name of the field at an index.
*
* GetFieldType() - The data type of the field at an index.
*
* NextRow() - Advances the query results by one row, and returns whether
* there are more rows left in the query.
*
* DataValue() - Extract a single data value from the current row.
*
* @par Thanks:
* Thanks to Andrew Wilson from Sandia National Laboratories for his work
* on the database classes.
*
* @sa
* vtkRowQueryToTable
*/
#ifndef vtkRowQuery_h
#define vtkRowQuery_h
#include "vtkIOSQLModule.h" // For export macro
#include "vtkObject.h"
class vtkVariant;
class vtkVariantArray;
class VTKIOSQL_EXPORT vtkRowQuery : public vtkObject
{
public:
vtkTypeMacro(vtkRowQuery, vtkObject);
void PrintSelf(ostream& os, vtkIndent indent) override;
/**
* Execute the query. This must be performed
* before any field name or data access functions
* are used.
*/
virtual bool Execute() = 0;
/**
* The number of fields in the query result.
*/
virtual int GetNumberOfFields() = 0;
/**
* Return the name of the specified query field.
*/
virtual const char* GetFieldName(int i) = 0;
/**
* Return the type of the field, using the constants defined in vtkType.h.
*/
virtual int GetFieldType(int i) = 0;
/**
* Return the index of the specified query field.
* Uses GetNumberOfFields() and GetFieldName()
* to match field name.
*/
int GetFieldIndex(const char* name);
/**
* Advance row, return false if past end.
*/
virtual bool NextRow() = 0;
/**
* Return true if the query is active (i.e. execution was successful
* and results are ready to be fetched). Returns false on error or
* inactive query.
*/
virtual bool IsActive() = 0;
/**
* Advance row, return false if past end.
* Also, fill array with row values.
*/
bool NextRow(vtkVariantArray* rowArray);
/**
* Return data in current row, field c
*/
virtual vtkVariant DataValue(vtkIdType c) = 0;
/**
* Returns true if an error is set, otherwise false.
*/
virtual bool HasError() = 0;
/**
* Get the last error text from the query
*/
virtual const char* GetLastErrorText() = 0;
//@{
/**
* Many databases do not preserve case in field names. This can
* cause GetFieldIndex to fail if you search for a field named
* someFieldName when the database actually stores it as
* SOMEFIELDNAME. This ivar controls whether GetFieldIndex()
* expects field names to be case-sensitive. The default is OFF,
* i.e. case is not preserved.
*/
vtkSetMacro(CaseSensitiveFieldNames, bool);
vtkGetMacro(CaseSensitiveFieldNames, bool);
vtkBooleanMacro(CaseSensitiveFieldNames, bool);
//@}
protected:
vtkRowQuery();
~vtkRowQuery() override;
bool CaseSensitiveFieldNames;
private:
vtkRowQuery(const vtkRowQuery&) = delete;
void operator=(const vtkRowQuery&) = delete;
};
#endif // vtkRowQuery_h