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FIELD
Field (column) definitions
------------------------------------------------------------------------------
Structure
typedef struct _FIELD
{
USHORT uiType;
USHORT uiTypeExtended;
USHORT uiLen;
USHORT uiDec;
USHORT uiArea;
FARP sym;
struct _FIELD * lpfNext;
} FIELD;
typedef FIELD far * LPFIELD;
Notes
The pointer to an array of FIELD structures is contained in the basic
AREA structure. Each field is created by a call to the addField()
method for a given RDD.
Elements
uiType
Contains a literal constant indicating the column's CA-Clipper data
type. The numeric constants used to indicate the data types are
defined in Extend.api and have the following meanings:
FIELD Data Types
---------------------------------------------------------------------
Constant Meaning
---------------------------------------------------------------------
CHARACTER A CA-Clipper character value
DATE A CA-Clipper date value
DOUBLE A CA-Clipper numeric value stored as an XDOUBLE by the
Extend System
LOGICAL A CA-Clipper logical value
MEMO A CA-Clipper memo value
NUMERIC A CA-Clipper numeric value stored as a LONG by the
Extend System
UNDEF The CA-Clipper NIL value
---------------------------------------------------------------------
uiTypeExtended
Contains a numeric value indicating a user-defined column type. This
member is used to provide support for column types not supported by
CA-Clipper's default database (.dbf) file format. The intrinsically
supported column types are character, numeric, date, logical, and
memo. A non-zero value in this field indicates that the column type
is not one of the intrinsically supported types. This allows the RDD
to support column types that are not intrinsically understood by
CA-Clipper. Extended types must be translated into CA-Clipper types
by the RDD and uiTypeExtended values are defined by the RDD.
uiLen
Contains a numeric value representing the overall length of the
column. RDDs supporting floating point column types should include
the decimal point in this value. By convention, variable length
columns should store a zero (0) in this element.
uiDec
Contains a numeric value indicating the number of places to the right
of the decimal point. This element is only meaningful when the
column is a floating point value.
uiArea
Contains a numeric value indicating the work area in which the field
resides. The CA-Clipper runtime system uses this field to reference
the appropriate work area.
sym
Contains a character data type value representing the column and
work area to the runtime system. The CA-Clipper runtime system will
interpret runtime requests (get or set actions) to this symbol as a
call to the your driver.
lpfNext
Reserved.
Files Header file is Rdd.api.
Used By AREA
See Also:
AREA
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