c-treeRTG COBOL Edition User's Guide

Type Mapping Table

To define an XDD file requires defining the data type of each column of the original data file. The following table describes the accepted XDD data types:

Type to be used in the XDD field specification	Type description
NumUnsigned	ASCII string representing an unsigned number
NumSignSep	ASCII string representing a signed number with trailing separate sign.
NumSigned	ASCII string representing a signed number with trailing sign
NumSepLead	ASCII string representing a signed number with leading separate sign
NumLeading	ASCII string representing a signed number with leading sign
Alphanum	ASCII string
Float	Float or Double values
CompSigned	Signed computational
CompUnsigned	Unsigned computational
PackedPositive	Packed string representing a positive number
PackedSigned	Packed string representing a signed number
PackedUnsigned	Packed string representing an Unsigned number
BinarySigned	Integer number represented in binary signed format (big endian)
BinaryUnsigned	Integer number represented in binary unsigned format (big endian)
NativeSigned	Integer number represented in native O/S binary signed format
NativeUnsigned	Integer number represented in native O/S binary unsigned format

See also <schema> table element.

In This Section Variable-length fields mapped into LONGVAR* SQL field

Variable-length fields mapped into LONGVAR* SQL field

Variable length fields map into SQL LONGVAR* fields.

The XDD structure allows the following elements and attributes for variable length field support.

1. dbtype values:
   • BLOB: Indicates a variable-length binary object with length depending on a field value.
   • CLOB: Indicates a variable-length text object with length depending on a field value.
2. <field> attribute sizefield used in conjunction with dbtype BLOB or CLOB and having size = "0"

For an XDD field mapped into a LONG VARCHAR or LONG VARBINARY, the following conditions must be met:

1. The field definition must have:

   size="0"

   sizefield="X" where "X" is a valid field containing the number of bytes (we suggest this field to be hidden, but this is not mandatory)

   dbtype="clob" or dbtype="blob"

2. At maximum, one and only one field mapped to a BLOB or CLOB type.
3. It must be the last field in the record buffer.

If one (or more) of the above condition is not met, error CTDBRET_CALLBACK_11 ("Unsupported clob/blob definition") is returned.