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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]
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For example:
>DATA-SETS=PAYROLL,ACCTREC
>DATA-SETS=
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Parameter | |
- 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
than 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
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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
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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
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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
>
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