JFLD (Joined Fields) Keyword— — Join Logical Files Only
Use this join-level keyword to identify the from and to fields whose values are used
to join physical files in a join logical file. These fields are both referred to as join
The format of the keyword is:
The join fields must correspond to fields in the physical files identified on the
JOIN keyword for this join specification. The name you specify on the JFLD
keyword must be the same as the name specified in the physical file unless it was
renamed in the join logical file. If you do not specify a JOIN keyword, then the
JFILE keyword is used.
This keyword is valid only for join logical files.
At least one JFLD keyword is required for each join specification. A join
specification is identified by J in position 17. Since at least one join specification is
required in a join logical file, you must have at least one JFLD keyword specified
in a join logical file.
These fields need not also be specified as fields in the record format for a join
To specify additional join fields to use when joining physical files, specify more
than one JFLD keyword.
The field names you specify on the JFLD keyword must either be specified at the
field level in the join record format or in one of the physical files, which are
specified on the JFILE keyword.
The OS/400 program uses the following search order to match join field names
with defined fields:
Fields specified in the join logical file at the field level in positions 19 through
Note: Fields that specify the CONCAT, RENAME, or SST keywords are valid
as join fields; fields that are specified on CONCAT, RENAME, or SST
keywords cannot be join fields.
Fields in the physical file specified on the JOIN keyword.
The rules for specifying join fields are as follows:
v The from field must be found in the from file specified on the JOIN keyword.
v The to field must be found in the to file specified on the JOIN keyword.
v Join fields are not required to be defined in the join record format.
v From and to fields must have the same field attributes (length, data type, and
decimal positions) but need not have the same name. When the joined fields in
the physical files have different definitions, you must redefine one or both fields.
If you redefine fields, there is a possibility of data conversion errors. See “DDS
Length for physical and logical files (Positions 30 through 34)” on page 36, “DDS
Data Type for physical and logical files (Position 35)” on page 39, “DDS Decimal
Positions for physical and logical files (Positions 36 and 37)” on page 41, and
“DDS Usage for physical and logical files (Position 38)” on page 43.
Physical and Logical Files, JFLD
OS/400 DDS Reference V4R5