wxDbColDef

This class is used to hold information about the columns bound to an instance of a wxDbTable object.

Each instance of this class describes one column in the wxDbTable object. When calling the wxDb constructor, a parameter passed in indicates the number of columns that will be defined for the wxDbTable object. The constructor uses this information to allocate adequate memory for all of the column descriptions in your wxDbTable object. Private member wxDbTable::colDefs is a pointer to this chunk of memory maintained by the wxDbTable class (and can be retrieved using the wxDbTable::GetColDefs function). To access the nth column definition of your wxDbTable object, just reference wxDbColDefs element [n - 1].

Typically, wxDbTable::SetColDefs is used to populate an array of these data structures for the wxDbTable instance.

Currently there are no accessor functions for this class, so all members are public.

    wxChar  ColName[DB_MAX_COLUMN_NAME_LEN+1];  // Column Name
    int     DbDataType;    - Logical Data Type;
                             e.g. DB_DATA_TYPE_INTEGER
    SWORD   SqlCtype;      - C data type; e.g. SQL_C_LONG
    void   *PtrDataObj;    - Address of the data object
    int     SzDataObj;     - Size, in bytes, of the data object
    bool    KeyField;      - Is column part of the PRIMARY KEY for the
                             table? -- Date fields should NOT be
                             KeyFields
    bool    Updateable;    - Column is updateable?
    bool    InsertAllowed; - Column included in INSERT statements?
    bool    DerivedCol;    - Column is a derived value?
    SDWORD  CbValue;       - !!!Internal use only!!!
    bool    Null;          - NOT FULLY IMPLEMENTED
                             Allows NULL values in Inserts and Updates

See also

database classes overview, wxDbTable::GetColDefs, wxDb constructor

Include files

<wx/db.h>



wxDbColDef::Initialize

Simply initializes all member variables to a cleared state. Called by the constructor automatically.

ymasuda 平成17年11月19日