tabrelation.h

来自「linux下一款GIS程序源码」· C头文件 代码 · 共 87 行

// tabrelation.h: interface for the TABRelation class.
//
/*---------------------------------------------------------------------
 *                      class TABRelation
 *
 * Class that maintains a relation between 2 tables through a field
 * in each table (the SQL "where table1.field1=table2.field2" found in 
 * TABView datasets).
 *
 * An instance of this class is used to read data records from the
 * combined tables as if they were a single one.
 *--------------------------------------------------------------------*/

#ifndef  TABRelation_H
#define  TABRelation_H

#include "tabfile.h"

class TABRelation  
{
  private:
    /* Information about the main table.
     */
    TABFile     *m_poMainTable;
    char        *m_pszMainFieldName;
    int         m_nMainFieldNo;

    /* Information about the related table.  
     * NOTE: The related field MUST be indexed.
     */
    TABFile     *m_poRelTable;
    char        *m_pszRelFieldName;
    int         m_nRelFieldNo;

    TABINDFile  *m_poRelINDFileRef;
    int         m_nRelFieldIndexNo;

    int         m_nUniqueRecordNo;

    /* Main and Rel table field map:
     * For each field in the source tables, -1 means that the field is not
     * selected, and a value >=0 is the index of this field in the combined
     * FeatureDefn
     */
    int         *m_panMainTableFieldMap;
    int         *m_panRelTableFieldMap;

    UGKFeatureDefn *m_poDefn;

    void        ResetAllMembers();
    UGKByte       *BuildFieldKey(TABFeature *poFeature, int nFieldNo,
                                  TABFieldType eType, int nIndexNo);

public:
	TABRelation();
	virtual ~TABRelation();

    int         Init(const char *pszViewName,
                     TABFile *poMainTable, TABFile *poRelTable,
                     const char *pszMainFieldName,
                     const char *pszRelFieldName,
                     char **papszSelectedFields);
    int         CreateRelFields();

    UGKFeatureDefn *GetFeatureDefn()  {return m_poDefn;};
    TABFieldType    GetNativeFieldType(int nFieldId);
    TABFeature     *GetFeature(int nFeatureId);

    int         SetFeature(TABFeature *poFeature, int nFeatureId=-1);

    int         SetFeatureDefn(UGKFeatureDefn *poFeatureDefn,
                           TABFieldType *paeMapInfoNativeFieldTypes=NULL);
    int         AddFieldNative(const char *pszName, TABFieldType eMapInfoType,
                               int nWidth=0, int nPrecision=0,
                               UGKBool bIndexed=FALSE, UGKBool bUnique=FALSE);

    int         SetFieldIndexed(int nFieldId);
    UGKBool       IsFieldIndexed(int nFieldId);
    UGKBool       IsFieldUnique(int nFieldId);

    const char *GetMainFieldName()      {return m_pszMainFieldName;};
    const char *GetRelFieldName()       {return m_pszRelFieldName;};

};

#endif