HP 3000 Manuals HP 3000 Manuals
DATA-SETS=
Informs QUERY which data set to reference in the primary data base if a
data item name which appears in more than one data set is used in a FIND,
LIST, REPORT, or UPDATE command.
Syntax
[DATA-SET]S= [data set list]
For example:
>DATA-SETS=PAYROLL,ACCTREC
>DATA-SETS=
Parameters
data set list is a list of data sets you want to access. The
list can contain data set names and dummy data set
names. Each name must be separated from the next
name by a comma. If data set list is not
included, the data set list is cleared.
A dummy data set is a temporary data set used in
the JOIN command. The dummy data set is cleared
from the data set list when the next JOIN command
is entered.
Discussion
The DATA-SETS= command defines a list of one or more data sets. If you
use a FIND, MULTIFIND, SUBSET, REPORT, or LIST command with a data item
name which is in more than one data set in the primary data base, QUERY
will check the data set list to determine which data set to use.
In an IMAGE data base, different data items can have the same name if
each appears in a different data set. As mentioned in Section 1, you can
use a fully-qualified data item name (data set name.data item name) to
tell QUERY which data item to use. However, if you are using
fully-qualified names for multiple data items, the command could become
quite lengthy. The DATA-SETS= command may save you some time.
Data Set Selection Rules
Session Mode
If you reference a data item appearing in more that one data set, QUERY
resolves which data set to use according to the following rule:
* If one (and only one) of the data sets containing the data item
appears in the data set list, QUERY automatically uses that data set.
Otherwise QUERY prompts you to supply the desired data set with the
message:
data item name IS A MEMBER OF THESE SETS:
data set name,data set name,....
WHICH SET DO YOU WISH TO USE?
>>data set name
You must type the name of the data set you want to access. If the name
you provide does not match the names listed, QUERY repeats the prompt.
If you decide you do not want to access the listed data sets, you may
abort the command by pressing RETURN instead of entering a data set name.
You will be prompted for another command.
Job Mode
QUERY cannot prompt you for the desired data set in the event of
ambiguity. The data set to be accessed is chosen according to the
following rules:
* If exactly one data set containing the data item appears in the data
set list, QUERY uses that data set.
* If more than one of the data sets containing the data item appears in
the data set list, QUERY uses the last data set mentioned in the
list.
* If no data set containing the data item is in the data set list,
QUERY accesses the last data set in the data base that contains the
data item and to which you have access. You may want to use the FORM
data item name command in session mode before you prepare your job to
determine the order of the data sets that include the data item. You
can then decide what to include in the data set list.
QUERY will inform you of which data set was chosen, if there is any
ambiguity, with this message:
data item name IS A MEMBER OF THESE SETS:
data set name,data set name,....
data set name USED
Automatic Data Set List Additions
If a FIND or LIST command is executed which contains an unqualified data
item name (i.e. a data item without a preceding data set name), QUERY
automatically adds the name of the accessed data set to the data set
list. This occurs whether the named data item appears in more than one
data set or not.
To avoid any ambiguity when the name data item appears in multiple data
sets, you can do one of two things:
* Use fully-qualified data item names in all commands.
* Always reset the data set list with the DATA-SETS= command prior to
entering a command using a data item which appears in multiple sets.
Examples
Example 1
This example illustrates the DATA-SETS= command. Data set names are
entered into the data set list. When the DEFINE command is issued, you
can see which sets are currently in the list.
>S=INVENTORY,SALES
>DEFINE
DATA-BASE = ORDERS.PUB.SYS
DATA-BASE = >>RETURN
PASSWORD = **********
PASSWORD = >>RETURN
MODE = 1
MODE = >>RETURN
DATA-SETS = INVENTORY,SALES
DATA-SETS = >>RETURN
PROC-FILE = >>RETURN
OUTPUT = TERM
OUTPUT = >>RETURN
>
Example 2
This example illustrates how QUERY uses the data set list, clears it, and
enters data set names automatically. The DEFINE command shows that the
data set list currently contains the SALES data set. When using the FIND
command to search entries with STOCK#=6650D22S, the SALES data set is
automatically used since it is in the data set list. The DATA SET=
command, followed by no data set names, clears the data set list. When
FIND STOCK=6650D22S is used again, QUERY prompts for the data set to be
used. The DEFINE command shows that the data set INVENTORY was
automatically added to the data set list. When FIND STOCK#=7391Z22F is
entered, the INVENTORY data set is used. However, in the next FIND
command, the data set SALES is specified. In this case, the data set
list is not used.
>DEFINE
DATA-BASE = ORDERS.PUB.SYS
DATA BASE = >>RETURN
PASSWORD = **********
PASSWORD = >>RETURN
MODE = 1
MODE = >>RETURN
DATA-SETS = SALES
DATA-SETS = >>RETURN
PROC-FILE = MANPROC.IMAGE.DATAMGT
PROC-FILE = >>RETURN
OUTPUT = TERM
OUTPUT = >>RETURN
>FIND STOCK#=6650D22S
2 ENTRIES QUALIFIED
>DATA-SETS=
>FIND STOCK#=6650D22S
STOCK# IS A MEMBER OF THESE SETS:
PRODUCT,SALES,INVENTORY
WHICH SET DO YOU WISH TO USE?
>>INVENTORY
5 ENTRIES QUALIFIED
>DEFINE
DATA-BASE = ORDERS.PUB.SYS
DATA-BASE = >>RETURN
PASSWORD = **********
PASSWORD = >>RETURN
MODE = 1
MODE = >>RETURN
DATA-SETS = INVENTORY
DATA-SETS = >>RETURN
PROC-FILE = MANPROC.IMAGE.DATAMGT
PROC-FILE = >>RETURN
OUTPUT = TERM
OUTPUT = >>RETURN
>FIND STOCK#=7391Z22F
2 ENTRIES QUALIFIED
>FIND SALES.STOCK#= 7391Z22F
8 ENTRIES QUALIFIED
>