
JOIN
Data
Item
Types
Equated
(joined)
data
items
can
b e
of
dieren
t
t
yp es
and
lengths,
with
the
exception
of
c
haracter
t
yp es,
whic
h
may
only
b e
equated
to
other
c
haracter
t
yp es.
If
t
w
o
items
of
dieren
t
lengths
are
equated,
QUER
Y
treats
the
shorter
one
as
if
it
w
ere
padded
with
blanks
to
match
the
length
of
the
longer
data
item.
Nul
l
Conne
cting
Data
Items
The
IMA
GE
subsystem
initializes
n
umeric
t
yp e
data
items
to
zero,
and
c
haracter
t
yp e
data
items
to
ASCI I
n
ull.
When
data
items
are
equated
with
a
relational
op erator
for
retriev
al,
QUER
Y
compares
data
item
v
alues
based
on
their
t
yp es.
When
comparing
t
w
o
n
umeric
t
yp e
data
items,
QUER
Y
considers
the
t
w
o
items
equal
when
b oth
items
ha
v
e
a
zero
v
alue.
If
the
comparison
is
b et
w
een
c
haracter
t
yp e
data
items
with
the
v
alues
of
ASCI I
n
ull,
QUER
Y
do es
not
consider
the
relationship
equal,
and
no
en
tries
are
joined.
Zone
d
T
yp
e
Data
Items
When
joining
zoned
t
yp e
data
items,
the
zoned
n
um
b ers
with
the
sign
o
v
erpunc
h
are
considered
equal
to
the
equiv
alen
t
v
alue
without
an
o
v
erpunc
h.
F
or
example,
5A
is
considered
equiv
alen
t
to
51.
When
QUER
Y
con
v
erts
a
dieren
t
data
t
yp e
to
zoned,
it
will
pad
with
leading
blanks.
Leading
n
ulls
are
not
considered
equiv
alen
t
to
leading
blanks.
Packe
d
Data
T
yp
e
Items
When
QUER
Y
con
v
erts
a
dieren
t
data
t
yp e
to
pac
k
ed,
it
uses
a
COBOL
Con
v
en
tion,
a
p ositiv e
sign
of
1100,
a
negative
sign
of
1101,
and
unsigned
1111.
P
ositive
and
unsigned
n
um
b ers
are
considered
equiv
alen
t.
Data
Set
Equiv
alence
Equating
data
sets
is
a
w
a
y
of
renaming
a
data
set
to
enable
the
information
con
tained
in
it
to
b e
used
in
more
than
one
w
a
y
.
F
or
example,
assume
y
ou
ha
v
e
the
follo
wing
simple
data
set
EMP-DET
AIL
con
taining
three
data
en
tries,
and
y
ou
w
an
t
to
create
a
REPOR
T
that
prin
ts
the
emplo
y
ee's
name
and
the
emplo
y
ee's
manager's
name:
EMP-DETAIL
--------------------------------------------------------- ---------
EMP-#
EMP-NAME
MGR-#
--------------------------------------------------------- ---------
1792
G.
Smith
1833
1833
H.
Jones
3421
3421
J.
President
****
--------------------------------------------------------- ---------
In
this
data
set,
the
data
item
MGR#
iden
ties
b oth
an
emplo
y
ee
and
an
emplo
y
ee's
manager.
F
or
example,
MGR#
1833
iden
ties
G.
Smith's
manager
(H.
Jones)
and
is
at
the
same
time
H.
Jones
emplo
y
ee
n
um
b er.
T
o
create
the
desired
rep ort,
the
data
set
EMP-DET
AIL
m
ust
b e
equated
to
a
dumm
y
data
set,
and
these
t
w
o
data
sets
connected
with
a
JOIN
command,
to
sp ecify
a
comp ound
data
set
from
whic
h
the
rep ort
can
b e
generated.
The
dumm
y
data
set
MGR-DET
AIL
is
a
temp orary
name
to
whic
h
the
existing
data
set
is
equated.
Note
that
this
equation
m
ust
b e
sp ecied
after
the
data
item
equiv
alences.
> JOIN
EMP-DETAIL.MGR-#
TO
MGR-DETAIL.EMP-#;&
>>
MGR-DETAIL
=
EMP-DETAIL
> MULTIFIND
ALL
QUERY/V
COMMANDS
3-59
Summary of Contents for QUERY
Page 10: ......
Page 17: ...Figure 1 1 ORDERS Data Base Structure Figure 1 2 Sample Entry Values INTRODUCING QUERY V 1 7 ...
Page 20: ...Figure 1 3 IMAGE QUERY Environments 1 10 INTRODUCING QUERY V ...
Page 36: ......
Page 165: ...REPORT G1 GROUP TITLE 11 END QUERY V COMMANDS 3 129 ...
Page 199: ...XEQ TF TOTAL DUE 9 SPACE B2 SKIP A TF R0 70 E2 S PURCH DATE END QUERY V COMMANDS 3 163 ...
Page 200: ......
Page 244: ......
Page 278: ......
Page 279: ...G ASCII CHARACTER SET This appendix is not available in this edition ASCII CHARACTER SET G 1 ...
Page 280: ......