Field attribute combinations

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Combining attributes

When deciding on combinations of field attributes, use the chart in Combining attributes to see if the combination you want to use is valid, See Key to table for combining attributes.

Field attribute combinations
Attribute KEY ORD CHAR ORD NUM FRV UNQ NR DEF LVL ONE INV STR FLT BIN COD FV OCC LEN PAD UPD BLOB CLOB
KEY                                       N N
ORD CHAR     N N               N               N N
ORD NUM   N   N   N                           N N
FRV R N N   N                             N N
UNIQUE (UNQ)   @ @ N     N                         N N
NUM RANGE (NR)     N                 N       =1       N N
DEFERRABLE (DEF) @ @ @   N @                           N N
(LVL)                                          
AT-MOST-ONE (ONE)                   N                      
INVISIBLE (INV) @ @ @     @     N     N       N N N N N N
STRING (STR)                       N N             N N
FLOAT (FLT)   N       N       N N   N F     R N   N N
BINARY (BIN)                     N N         N N   N N
CODED (COD)                       F         F N   N N
FEW VALUED (FV)         @                 @           N N
OCCURS (OCC)           =1     =1 N     @ @     @        
LENGTH (LEN)                   N   @ N F   @       N N
PAD                   N   N N N     R     N N
UPDATE (UPD)                   N                      
BINARY_LARGE_OBJECT (BLOB) N N N N N N N     N N N N N N   N N     N
CHARACTER_LARGE_OBJECT (CLOB) N N N N N N N     N N N N N N   N N   N  

Key to table for combining attributes

Code Meaning
N This attribute combination is not valid.
R This attribute combination is required.
@ One of these attributes is required. You can choose any one of the attributes marked, but you must choose at least one.
=1 The OCCURS clause is valid with this attribute only if defined as OCCURS=1. You cannot enter multiple field values for fields with these attributes.
F The FLOAT attribute requires the LEN attribute. Since the FLOAT attribute can also be used with the CODED attribute, this is the only circumstance that the LEN attribute is valid with CODED attribute.

Some of the invalid combinations are direct conflicts, such as UNIQUE and DEFERRABLE; others describe meaningless situations or unusable fields, such as ORDERED CHARACTER and ORDERED NUMERIC.

In addition, some attributes require other attributes. FLOAT, for example, requires a LENGTH specification.

Field descriptions that contain invalid combinations are rejected.

Combining attributes is for Entry Order files. More stringent restrictions are placed on fields that are used as sort keys, hash keys, or record security fields. These restrictions are summarized in the discussion in the Model 204 Parameter and Command Reference.

Field description worksheet

You can use Field description worksheet, the sample worksheet, to gather information about each field during file design. You can easily refer to it while calculating space requirement and writing File Load utility statements.

File description sheet for file_______________________________________

FLOD

option
                                           
Non-default Field Attributes LOB                                          
UNIQ Bits                                          
LVL                                          
PAD                                          
LEN                                          
OCC                                          
NDF                                          
FV                                          
BIN                                          
ONE                                          
FLT                                          
COD                                          
UE                                          
ORD                                          
FRV                                          
NV                                          
NR                                          
KEY                                          

Number Unique

Values
                                         
FLOD Input Length                                          
Input Position                                          
Field Name