Chapter 4 ActiveX Client Interfaces

Field interface

Description

Type library name	JaguarTypeLibrary
DLL name	jagproxy.dll

Represents one column in a row of tabular data.

Type - Integer. Returns a constant that indicates the column's datatype. "The Field.Type and Field.Value properties" lists possible values.
Value - Variant. Returns the column's value in the Variant type that matches the column's database type. "The Field.Type and Field.Value properties" lists SQL datatypes and the corresponding Variant types.
ActualSize - Integer. For string and binary data, returns the length of the current value.
DefinedSize - Integer. For string and binary data, returns the maximum length that values in the column may have.
Name - String. Returns the column's name.
NumericScale - Integer. For fixed-precision numeric values, returns the column's scale. The scale is the number of decimal digits to the right of the decimal point.
OriginalValue - Same as the Value property.
Precision - Integer. For fixed-precision numeric values, returns the column's precision. The precision is the number of decimal digits in the value.
UnderlyingValue - Same as the Value property.

Usage

For sample code that accesses a Field object's properties, see "Creating ActiveX Clients" in the EAServer Programmer's Guide.

Table 4-1 lists SQL datatypes, the corresponding values for the Type property, and the corresponding Variant datatypes for the Value property. Values for the type property are defined in the DataTypeEnum enumeration. The table lists both the symbolic DataTypeEnum values and the numeric constants that they represent. Some automation controllers may not be able to use symbolic values from an enumeration; in these controllers, use the numeric constant instead.

Table 4-1: The Field.Type and Field.Value properties
SQL datatype	Field.Type constant	Field.Value return type
BIT, or 1 bit of data	adBoolean (11)	VT_BOOL (1 maps to `true` )
TINYINT, an 1-byte integer	adTinyInt (16)	VT_UI1
SMALLINT, a 2-byte integer	adSmallInt (2)	VT_I2
INTEGER, a 4-byte integer	adInteger (3)	VT_I4
FLOAT, an 8-byte floating point number	adDouble (5)	VT_R8
CHAR, string values that do not vary in length	adChar (129)	VT_BSTR
VARCHAR, string values that can vary in length	adVarChar (200)	VT_BSTR
BINARY, an array of bytes that does not vary in length	adBinary (128)	VT_ARRAY
VARBINARY, an array of bytes that may vary in length	adVarBinary (204)	VT_ARRAY
NUMERIC, a fixed-point decimal number	adNumeric (131)	VT_R8 (No direct mapping exists. Mapped to 8-byte floating point)
DECIMAL, a fixed-point decimal number	adDecimal (14)	VT_R8 (No direct mapping exists. Mapped to 8-byte floating point)
DATE, a date value including the time-of-day	adDate (7)	VT_DATE
MONEY, a cash value	adCurrency (6)	VT_CY

Field interface

Description

Usage

See Also