HP QUERY, Reference Manual, Page: 249 / 280

10 = IMA GE comp ound item
The item t yp es in paren theses corresp ond to IMA GE data t yp es.
Note: T yp e 2 refers to ASCI I represen tations of n um b ers in free format. This
includes 20, 45.7, 1.002E-10, -201.45.
item oset is the oset of the item in the le record in b ytes. This oset is relativ e to the
b eginning of the b eginning of a record where the rst b yte has an oset of
zero, the second has an oset of one, and so on. (integer)
item length is the length of the item in b ytes. This distinguishes the long and short forms
of in tegers and reals. (integer)
r eserve d sp ac e is reserv ed for future enhancemen ts to SD les. F our w ords are reserv ed.
ITEM NAMES
All item names in a self-describing le m ust b e unique unless all the duplicate items are in
data item equiv alences. (Refer to the JOIN command for more information on data item
equiv alences.)
En tries retrieved with a FIND ha v e unique item names b ecause they are retrieved from a
single data set. Ho w ev er, en tries retrieved with a MUL TIFIND may ha v e duplicate item
names b ecause they are retrieved from more than one data set. The duplicate items m ust
ha v e b een used in the JOIN data item equiv alence(s). An exception is made b ecause the
duplicate items are of the same v alue although they may b e of dieren t data t yp es.
The rst o ccurence of the item in the comp ound data set en try is the one recorded in the
item description. Other o ccurences are skipp ed b ecause the item has already b een describ ed.
The data in the le con tains all o ccurences of the data item ev en though the item description
app ears only once. The oset reects the rst lo cation in the record where the data item
v alue can b e accessed.
Refer to example 2 for a self-describing le created from a MUL TIFIND where the JOIN item
names are iden tical.
Examples
Example 1 - Single Data Set R etrieval
Given the following IMA GE data base:
BEGIN DATA BASE SD;
PASSWORDS:
ITEMS:
NAME, U10;
OCCUP, U16;
CITY, U10;
STATE, I2; << contains a numeric code for each state >>
SETS:
NAME: SET1, D;
ENTRY: NAME, OCCUP, CITY, STATE;
CAPACITY: 11;
END.
SELF-DESCRIBING FILES E-3