END-ALL
|
||||||||||
[AND ]
|
||||||||||
SORT
|
THEM
|
[BY ]
|
operand1 |
ASCENDING
|
10 | |||||
RECORDS
|
DESCENDING
|
|||||||||
USING-clause | ||||||||||
[GIVE-clause] | ||||||||||
statement | ||||||||||
END-SORT
|
* If a
statement
label is specified, it must be placed before the keyword
SORT
, but after END-ALL
(and
AND
).
SORT
|
THEM
|
[BY ]
|
operand1 |
ASCENDING
|
10 | |||||
RECORDS
|
DESCENDING
|
|||||||||
[USING-clause] | ||||||||||
[GIVE-clause] | ||||||||||
statement | ||||||||||
LOOP |
This document covers the following topics:
For explanations of the symbols used in the syntax diagram, see Syntax Symbols.
Related Statement: FIND
with SORTED BY
option
Belongs to Function Group: Loop Execution
The SORT
statement is used to perform a sort operation,
sorting the records from all processing loops that are active when the
SORT
statement is executed.
Note:
Natural creates a temporary work file during the sort
operation. If you specify the TMPSORTUNIQ
profile parameter (see the Parameter Reference
documentation), Natural generates a unique name for the temporary sort work
file.
The SORT
statement must be contained in the same object
as the processing loops whose records it sorts.
Nested SORT
statements are not allowed.
The total length of a record to be sorted must not exceed 10240 bytes.
The number of sort criteria must not exceed 10.
Operand Definition Table:
Operand | Possible Structure | Possible Formats | Referencing Permitted | Dynamic Definition | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
operand1
|
S | A | N | P | I | F | B | D | T | no | no |
Syntax Element Description:
Syntax Element | Description |
---|---|
END-ALL
|
Closing All Currently Active Loops:
In structured mode, the Note: |
operand1
|
Sort Criteria:
|
ASCENDING
|
Sort Sequence:
The default sort sequence is ascending. If you wish the values to
be sorted in descending sequence, specify
|
DESCENDING
|
|
USING |
USING Clause:
See USING Clause below. |
GIVE |
GIVE Clause:
See GIVE Clause below. |
END-SORT
|
End of SORT Statement:
In structured mode, the Natural reserved word In reporting mode, the Natural statement |
LOOP |
The USING
clause indicates the fields which are to be
written to intermediate sort storage. It is required in structured mode and
optional in reporting mode. However, it is strongly recommended to also use it
in reporting mode so as to reduce memory requirements.
|
Operand Definition Table:
Operand | Possible Structure | Possible Formats | Referencing Permitted | Dynamic Definition | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
operand2
|
S | A | A | N | P | I | F | B | D | T | L | C | no | no |
Syntax Element Description:
In Reporting Mode: If you omit the USING
clause,
all database fields of processing loops initiated before the SORT
statement, as well as all user-defined variables defined before the
SORT
statement, will be written to intermediate sort storage.
If, after sort execution, a reference is made to a field which was not written to the sort intermediate storage, the value for the field will be the last value of the field before the sort.
The GIVE
clause is used to specify Natural system
functions (such as MAX
,
MIN
) that
are to be evaluated in the first phase of the SORT
statement.
These system functions may be referenced in the third phase (see
SORT Statement
Processing).
A reference to a system function after the SORT
statement
must be preceded by an asterisk, for example, *AVER(SALARY)
.
Note:
In place of the keyword GIVE
, the
keyword GIVING
may be used.
MAX
|
||||||||||
MIN
|
||||||||||
NMIN |
||||||||||
COUNT |
||||||||||
GIVE
|
NCOUNT |
[OF ]
|
(operand3 ) | [(NL= nn)]
|
||||||
OLD |
operand3 | |||||||||
AVER |
||||||||||
NAVER |
||||||||||
SUM |
||||||||||
TOTAL |
Operand Definition Table:
Operand | Possible Structure | Possible Formats | Referencing Permitted | Dynamic Definition | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
operand3
|
S | A | * | yes | no |
* depends on function
Syntax Element Description:
Syntax Element | Description |
---|---|
MAX |
MIN |
NMIN |
COUNT |
NCOUNT |
OLD |
AVER |
NAVER |
SUM |
TOTAL
|
System Functions:
For details on the individual system functions, see the System Functions documentation. |
operand3
|
Field Name:
|
(NL=nn.m)
|
Preventing Arithmetic Overflows:
This option applies to the system functions
This option may be used to prevent an arithmetic overflow during the evaluation of system functions; it is described under Format/Length Requirements for AVER, NAVER, SUM and TOTAL in the System Functions documentation. |
A program containing a SORT
statement is executed in three
phases.
The statements before the SORT
statement are executed. Data
as described in the USING
clause will be written to
intermediate sort storage.
In reporting mode, any variables to be used as accumulators following
the sort must not be defined before the SORT
statement. In
structured mode, they must not be included in the
USING
clause. Fields
written to intermediate sort storage cannot be used as accumulators because
they are read back with each individual record during the 3rd processing phase.
Consequently, the accumulation function would not produce the desired result
because with each record the field would be overwritten with the value for that
individual record.
The number of records written to intermediate storage is determined by
the number of processing loops and the number of records processed per loop.
One record on the internal intermediate storage is created each time the
SORT
statement is encountered in a processing loop. In the case of
nested loops, a record is only written to intermediate storage if the inner
loop is executed. If in the example below a record is to be written to
intermediate storage even if no records are found for the inner
(FIND
) loop, the FIND
statement must contain an
IF NO RECORDS
FOUND
clause.
READ ... ... FIND ... ... END-ALL SORT ... DISPLAY ... END-SORT ...
The records are sorted.
The statements after the SORT
statement are executed for
all records on the intermediate storage in the specified sorting sequence.
Database fields to be referenced after a SORT
statement must be
correctly referenced using the appropriate statement label or reference
number.
** Example 'SRTEX1S': SORT (structured mode) ************************************************************************ DEFINE DATA LOCAL 1 EMPL-VIEW VIEW OF EMPLOYEES 2 CITY 2 SALARY (1:2) 2 PERSONNEL-ID 2 CURR-CODE (1:2) * 1 #AVG (P11) 1 #TOTAL-TOTAL (P11) 1 #TOTAL-SALARY (P11) 1 #AVER-PERCENT (N3.2) END-DEFINE * LIMIT 3 FIND EMPL-VIEW WITH CITY = 'BOSTON' COMPUTE #TOTAL-SALARY = SALARY (1) + SALARY (2) ACCEPT IF #TOTAL-SALARY GT 0 /* END-ALL AND SORT BY PERSONNEL-ID USING #TOTAL-SALARY SALARY(*) CURR-CODE(1) GIVE AVER(#TOTAL-SALARY) /* AT START OF DATA WRITE NOTITLE '*' (40) 'AVG CUMULATIVE SALARY:' *AVER (#TOTAL-SALARY) / MOVE *AVER (#TOTAL-SALARY) TO #AVG END-START COMPUTE ROUNDED #AVER-PERCENT = #TOTAL-SALARY / #AVG * 100 ADD #TOTAL-SALARY TO #TOTAL-TOTAL /* DISPLAY NOTITLE PERSONNEL-ID SALARY (1) SALARY (2) #TOTAL-SALARY CURR-CODE (1) 'PERCENT/OF/AVER' #AVER-PERCENT AT END OF DATA WRITE / '*' (40) 'TOTAL SALARIES PAID: ' #TOTAL-TOTAL END-ENDDATA END-SORT * END
PERSONNEL ANNUAL ANNUAL #TOTAL-SALARY CURRENCY PERCENT ID SALARY SALARY CODE OF AVER --------- ---------- ---------- ------------- -------- ------- **************************************** AVG CUMULATIVE SALARY: 41900 20007000 16000 15200 31200 USD 74.00 20019200 18000 17100 35100 USD 83.00 20020000 30500 28900 59400 USD 141.00 **************************************** TOTAL SALARIES PAID: 125700
The previous example is executed as follows:
Records with CITY=BOSTON
are selected from the
EMPLOYEES
file.
The first 2 occurrences of SALARY
are accumulated in the
field #TOTAL-SALARY
.
Only records with #TOTAL-SALARY
greater than 0 are
accepted.
The records are written to the sort intermediate storage. The
database arrays SALARY
(first 2 occurrences) and
CURR-CODE
(first occurrence), the database field
PERSONNEL-ID
, and the user-defined variable
#TOTAL-SALARY
are written to the intermediate storage.
The average of #TOTAL-SALARY
is evaluated.
The records are sorted.
The sorted intermediate storage is read.
At the at-start-of-data condition, the average of
#TOTAL-SALARY
is displayed.
#TOTAL-SALARY
is added to #TOTAL-TOTAL
and
the fields PERSONNEL-ID
, SALARY(1)
,
SALARY(2)
, #AVER-PERCENT
and
#TOTAL-SALARY
are displayed.
At the end-of-data condition, the variable #TOTAL-TOTAL
is written.
Equivalent reporting-mode example: SRTEX1R.
** Example 'SRTEX2': SORT ************************************************************************ DEFINE DATA LOCAL 1 VEHIC-VIEW VIEW OF VEHICLES 2 MAKE 2 YEAR END-DEFINE * LIMIT 10 * READ VEHIC-VIEW END-ALL SORT BY MAKE YEAR USING KEY DISPLAY NOTITLE (AL=15) MAKE (IS=ON) YEAR AT BREAK OF MAKE WRITE '-' (20) END-BREAK END-SORT END
MAKE YEAR --------------- ----- FIAT 1980 1982 1984 -------------------- PEUGEOT 1980 1982 1985 -------------------- RENAULT 1980 1980 1982 1982 --------------------
In Natural, sort operations are by default processed by Natural's internal sort program, as described above. However, an external sort program can be used. This external sort program then processes the sort operations instead of Natural's internal sort program.
As external sort programs DMExpress Syncsort for UNIX and IRI CoSort for UNIX are supported.
Whether an external sort program is used or not, can be determined while you install Natural. For further information, see Re-Linking a Natural Nucleus in the Installation documentation.
The records that are to be sorted will be temporarily stored in
the directory specified under TMP_PATH
in the
Installation Assignments of your
Local Configuration File.