Use this field-level keyword to specify a character string that is a subset
of an existing character, hexadecimal, zoned field, or graphic.
The format of the keyword is:
SST(field-name starting-position [length])
The field-name parameter specifies the name of the field from which the
substring is taken. This field must be defined in the same logical file
format prior to the SST field (which is the field you are defining) or it must
exist in the physical file specified on the PFILE or JFILE keyword. To
find the field, the system searches for a matching field name as
follows:
- First, the system searches the field names specified in positions 19 to 28
in the logical file format prior to the SST field.
- If no matching field name is found in positions 19 to 28 in the logical
file format, the system searches for the field name in the physical file
specified on the PFILE or JFILE keyword, according to the following
rules:
- If the logical file is a simple or multiple format logical file, the field
must exist in all files specified on the PFILE keyword.
- If the logical file is a join logical file and the JREF keyword is
specified on the SST field, the field must exist in the JFILE referred to by
the JREF keyword.
- If the logical file is a join logical file and the JREF keyword is not
specified on the SST field, the field must exist in exactly one JFILE.
The substring begins at the starting position you specify on the SST
keyword. Specify its length either as the third parameter on the
keyword or on the field length (DDS positions 30 through 34). The
starting position is a required parameter; the length is optional.
- Note:
- Both the starting position and length values must be positive integer values
and the defined substring must not be greater than the length of the field
specified on the SST keyword.
The following rules apply:
- If the field on the SST keyword is hexadecimal, the resulting field is
hexadecimal; otherwise, the resulting field is always character.
If the data type is not specified in DDS, a default of H or A is
assigned.
- The use of the resulting field must be either input-only (I) or neither
(N).
- The length of the resulting field is optional. You must specify
either the field length or the length parameter on the keyword. If you
specify both, they must be equal. If the field length is not specified,
it is assigned the length parameter on the keyword.
- You cannot specify this keyword on the same field with the CONCAT, RENAME,
or TRNTBL keywords.
- The field specified on this keyword cannot be defined with the CONCAT,
TRNTBL, or SST keywords.
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