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Locates data entries from a detail data set and one or more of its
corresponding master data sets. Syntax | |
F[IND] CHAIN [#LIMIT=i;] item identifier {IS
IE
EQ
=} "value"
[{and
or} item identifier {IS
IE
EQ
=} "value" ] ... [END]
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For example:
>F CHAIN EMPLOYEE.BADGE#,LABOR.BADGE# IS "1234" OR&
>> EMPLOYEE.BADGE#,LABOR.BADGE# IS "9018"
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Where item identifier = EMPLOYEE.BADGE#,LABOR.BADGE#, and
"value" = "1234" or "9018"
>FIND CHAIN EMPLOYEE.BADGE#,LABOR.BADGE# IE "1234"
text
Where master set name = EMPLOYEE, master search item = BADGE#,
detail set name = LABOR, detail search item = BADGE#,
value = "1234"
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Parameters | |
- i
is an integer specifying the maximum number of qualifying entries
you want to retrieve. i must be >= 0. If you specify a negative number, QUERY ignores your input. When the #LIMIT = parameter is specified, only the first qualified entries are placed in the select file. If fewer than i entries exist, all entries that qualify are placed in the select file. - item identifier
takes the form:
master set name. master search item,
detail set name. detail search item
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master set name is the name of a master data set in the data base. master search item is the name of a data item defined as
the search item for the master data set. detail set name is the name of a detail data set that is
associated with the master data set previously named. detail search item is the name of a data item defined as a search item for the detail data set. This search item must
provide the link between the detail set and the previously
defined master set. value is a data item value. It must be the same type and
within the same value range as the master search item
and detail search item of the data item.
Value must be enclosed
in quotation marks only if it contains special characters or blanks.
Null values may be used. Refer to "Using Null Values" under the FIND command. Value must be an exact match for character type data items (type U or X). must be included in a procedure.
Discussion | |
Only one detail data set can be accessed using a FIND CHAIN
command, but multiple master sets can be used if they relate to the
same detail data set through search items. The data base administrator can provide you with the information
required to use this command, or you can use the FORM command to
determine the data item and data set relations. When you enter FIND CHAIN, QUERY searches the specified master
data sets for an entry containing the specified search item value.
Then QUERY searches the specified detail data set for entries containing the
same search item value. Detail entries with the same search item value
are called chains. The effect of FIND CHAIN is to locate all the members
of a detail chain and the master data entry which constitutes the chain head.
For more information on chains, chain heads, and data set relations,
consult the IMAGE Reference Manual. When using the FIND CHAIN command: Only selection on the basis of equality may be made. Relational
operators other than IS, IE, EQ, and = are not allowed. Only one value per relational operator is allowed. Data items named in the command must always be search items
(as defined in the data base). Up to 50 logical connectors (AND, OR) can appear in the same
command. Refer to the FIND command for more information about logical
connectors. No more than 16 values can be used in each FIND CHAIN command.
Example In the example below, CUSTOMER is searched for an entry
containing ACCOUNT equal to 76623455, and one entry is found.
Then PRODUCT is searched for an entry containing a STOCK# equal
to 6550D22S, and one entry is found. Then SALES is searched for
entries with both ACCOUNT equal to 76623455 and STOCK# equal to
6550D22S, but no entries are located. CUSTOMER is searched for
entries containing ACCOUNT equal to 54283545 and SALES is searched
for entries containing ACCOUNT equal to 54283545. One entry is found for
each relation. Note that both STOCK# and ACCOUNT are search items.
>FIND CHAIN CUSTOMER.ACCOUNT,SALES.ACCOUNT IS 76623455 AND&
>> PRODUCT.STOCK#,SALES.STOCK# IS 6550D22S OR&
>> CUSTOMER.ACCOUNT,SALES.ACCOUNT IS 54283545
4 ENTRIES QUALIFIED
>R ALL
ACCOUNT =76623455
LAST-NAME =MCFALL
FIRST-NAME =JEFFREY
INITIAL =X
STREET-ADDRESS =6650 MONTEREY ROAD
CITY =CARMEL
STATE =CA
ZIP =93921
CREDIT-RATING =3.20000
STOCK# =6550D22S
DESCRIPTION =BASEBALL BAT
ACCOUNT =54283545
LAST-NAME =MAYFIELD
FIRST-NAME =WILLIAM
INITIAL =
STREET-ADDRESS =39 41ST AVE.
CITY =PETALUMA
STATE =CA
ZIP =10101
CREDIT-RATING =8.50000
ACCOUNT =54283545
STOCK# =4397D13P
QUANTITY =1
PRICE =4590
TAX =276
TOTAL =0
PURCH-DATE =121585
DELIV-DATE =121685
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