Several Natural and non-Natural subprograms are available to provide you with internal information from Natural for DB2 or specific functions for which no equivalent Natural statements exist.
Natural subprograms are invoked with the Natural
CALLNAT
statement.
Non-Natural subprograms are invoked with the Natural
CALL statement.
| Subprogram | Function |
|---|---|
NDBCONV |
Sets or resets conversational mode 2. |
NDBERR |
Provides diagnostic information on the most recently executed SQL call. |
NDBISQL |
Executes SQL statements in dynamic mode. |
NDBNOERR |
Suppresses normal Natural error handling. |
NDBNROW |
Obtains the number of rows affected by a Natural SQL statement. |
NDBSTMP |
Provides a DB2 TIMESTAMP column as an alphanumeric
field and vice versa.
|
All these subprograms are provided in the Natural system library
SYSDB2 and the Natural library SYSTEM on the system
file FNAT.
For detailed information on these subprgrams, follow the links shown in
the table above and read the description of the call format and of the
parameters in the text member provided with the subprogram
(subprogram-nameT).
The Natural subprogram NDBCONV is used to either set or
reset the conversational mode 2 in CICS environments. Conversational mode 2
means that update transactions are spawned across terminal I/Os until either a
COMMIT or ROLLBACK has been issued (Caution DB2 and
CICS resources are kept across terminal I/Os!). This means conversational mode
2 has the same effect as the Natural profile parameter
PSEUDO=OFF, except
that the conversational mode is entered after an DB2 update statement
(UPDATE, DELETE, INSERT) and left again
after a COMMIT or ROLLBACK, while
PSEUDO=OFF causes conversational mode for the total Natural
session.
A sample program called CALLCONV is provided in library
SYSDB2; it demonstrates how to invoke NDBCONV. A
description of the call format and of the parameters is provided in the text
member NDBCONVT.
The calling Natural program must use the following syntax:
CALLNAT 'NDBCONV' #CONVERS #RESPONSE
The various parameters are described in the following table:
| Parameter | Format/Length | Explanation |
|---|---|---|
#CONVERS |
I1 | Contains the desired conversational mode(input) |
#RESPONSE |
I4 | Contains the response of NDBCONV(output)
|
The #CONVERS parameter can contain the following
values:
| Code | Explanation |
|---|---|
0 |
The conversational mode 2 has to be reset. |
1 |
The conversational mode 2 has to be set. |
The #RESPONSE parameter can contain the following
response codes:
| Code | Explanation |
|---|---|
0 |
The conversational mode 2 has been successfully set or reset. |
-1 |
The specified value of #CONVERS is
invalid, the conversational mode has not been changed.
|
-2 |
NDBCONV is called in a environment, which is not a
CICS environment, where the conversational mode 2 is not supported.
|
The Natural subprogram NDBERR replaces Function
E of the DB2SERV interface, which is still provided
but no longer documented. It provides diagnostic information on the most recent
SQL call. It also returns the database type which returned the error.
NDBERR is typically called if a database call returns a non-zero
SQL code (which means a NAT3700 error).
A sample program called CALLERR is provided on the
installation tape; it demonstrates how to invoke NDBERR. A
description of the call format and of the parameters is provided in the text
member NDBERRT.
The calling Natural program must use the following syntax:
CALLNAT 'NDBERR' #SQLCODE #SQLSTATE #SQLCA #DBTYPE
The various parameters are described in the following table:
| Parameter | Format/Length | Explanation |
|---|---|---|
#SQLCODE |
I4 | Returns the SQL return code. |
#SQLSTATE |
A5 | Returns a return code for the output of the most recently executed SQL statement. |
#SQLCA |
A136 | Returns the SQL communication area of the most recent DB2 access. |
#DBTYPE |
B1 | Returns the identifier (in hexadecimal format) for the currently
used database (where X'02' identifies DB2).
|
The Natural subprogram NDBISQL is used to execute SQL
statements in dynamic mode. The SELECT statement and all SQL
statements which can be prepared dynamically (according to the DB2 literature
by IBM) can be passed to NDBISQL.
A sample program called CALLISQL is provided on the
installation tape; it demonstrates how to invoke NDBISQL. A
description of the call format and of the parameters is provided in the text
member NDBISQLT.
The calling Natural program must use the following syntax:
CALLNAT 'NDBISQL'#FUNCTION #TEXT-LEN #TEXT (*) #SQLCA #RESPONSE #WORK-LEN #WORK (*)
The various parameters are described in the following table:
| Parameter | Format/Length | Explanation | |
|---|---|---|---|
#FUNCTION |
A8 | For valid functions, see below. | |
#TEXT-LEN |
I2 | Length of the SQL statement or of the buffer for the return area. | |
#TEXT |
A1(1:V) | Contains the SQL statement or receives the return code. | |
#SQLCA |
A136 | Contains the SQLCA. | |
#RESPONSE |
I4 | Returns a response code. | |
#WORK-LEN |
I2 | Length of the workarea specified by
#WORK (optional).
|
|
#WORK |
A1(1:V) | Workarea used to hold
SQLDA/SQLVAR and auxiliary fields across calls
(optional).
|
|
#DBTYPE |
I2 | Database type (optional). | |
0 |
Default | ||
2 |
DB2 | ||
4 |
CNX | ||
Valid functions for the #FUNCTION parameter
are:
| Function | Parameter | Explanation |
|---|---|---|
CLOSE |
Closes the cursor for the SELECT statement.
|
|
EXECUTE |
#TEXT-LEN |
Executes the SQL statement. |
FETCH |
#TEXT-LEN |
Returns a record from the |
TITLE |
|
Returns the header for the |
The #RESPONSE parameter can contain the following
response codes:
| Code | Function | Explanation |
|---|---|---|
5 |
EXECUTE |
The statement is a SELECT statement.
|
6 |
TITLE,
FETCH |
Data are truncated; only set on first TITLE or
FETCH call.
|
100 |
FETCH |
No record / end of data. |
-2 |
Unsupported data type (for example,
GRAPHIC).
|
|
-3 |
TITLE,
FETCH |
No cursor open; |
-4 |
Too many columns in result table. | |
-5 |
SQL code from call. | |
-6 |
Version mismatch. | |
-7 |
Invalid function. | |
-8 |
Error from SQL call. | |
-9 |
Workarea invalid (possibly relocation). | |
-10 |
Interface not available. | |
-11 |
EXECUTE |
First two bytes of statement not blank. |
The first call must be an EXECUTE call.
NDBISQL has a fixed SQLDA AREA holding space for 50 columns. If
this area is too small for a particular SELECT it is possible to
supply an optional work area on the calls to NDBISQL by specifying
#WORK-LEN (I2) and
#WORK(A1/1:V).
This workarea is used to hold the SQLDA and temporary work fields like
null indicators and auxiliary fields for numeric columns. Calculate 16 bytes
for SQLDA header and 44 bytes for each result column and 2 bytes null indicator
for each column and place for each numeric column, when supplying
#WORK-LEN and #WORK(*) during
NDBISQL calls. If these optional parameters are specified on an
EXECUTE call they have also to be specified on any following call.
If the statement is a SELECT statement (that is,
response code 5 is returned), any sequence of TITLE
and FETCH calls can be used to retrieve the data. A response code
of 100 indicates the end of the data.
The cursor must be closed with a CLOSE call.
Function code EXECUTE implicitly closes a cursor which has
been opened by a previous EXECUTE call for a SELECT
statement.
In TP environments, no terminal I/O can be performed between an
EXECUTE call and any TITLE, FETCH or
CLOSE call that refers to the same statement.
The Natural subprogram NDBNOERR is used to suppress Natural
NAT3700 errors caused by the next SQL call. This allows a program controlled
continuation if an SQL statement produces a non-zero SQL code. After the SQL
call has been performed, NDBERR is used to
investigate the SQL code.
A sample program called CALLNOER is provided on the
installation tape; it demonstrates how to invoke NDBNOERR. A
description of the call format and of the parameters is provided in the text
member NDBNOERT.
The calling Natural program must use the following syntax:
CALLNAT 'NDBNOERR'
There are no parameters provided with this subprogram.
Note:
Only NAT3700 errors (that is, non-zero SQL response codes) are
suppressed, and also only errors caused by the next following SQL call.
If NDBNOERR is called before a statement that initiates a
database loop and an initialization error occurs, no processing loop will be
initiated, unless a IF NO RECORDS FOUND clause has been
specified.
If NDBNOERR is called within a database loop, it does not
apply to the processing loop itself, but only to the SQL statement subsequently
executed inside this loop.
The Natural subprogram NDBNROW is used to obtain the number
of rows affected by the Natural SQL statements Searched UPDATE,
Searched DELETE, and INSERT. The number of rows
affected is read from the SQL communication area (SQLCA). A positive value
represents the number of affected rows, whereas a value of minus one
(-1) indicates that all rows of a table in a segmented tablespace
have been deleted; see also the Natural system variable
*NUMBER
as described in the Natural System Variables
documentation.
A sample program called CALLNROW is provided on the
installation tape; it demonstrates how to invoke NDBNROW. A
description of the call format and of the parameters is provided in the text
member NDBNROWT.
The calling Natural program must use the following syntax:
CALLNAT 'NDBNROW' #NUMBER
The parameter #NUMBER (I4) contains the number of
affected rows.
For DB2, Natural provides a TIMESTAMP column as an
alphanumeric field (A26) of the format
YYYY-MM-DD-HH.MM.SS.MMMMMM.
Since Natural does not yet support computation with such fields, the
Natural subprogram NDBSTMP is provided to enable this kind of
functionality. It converts Natural time variables to DB2 time stamps and vice
versa and performs DB2 time stamp arithmetics.
A sample program called CALLSTMP is provided on the
installation tape; it demonstrates how to invoke NDBSTMP. A
description of the call format and of the parameters is provided in the text
member NDBSTMPT.
The functions available are:
| Code | Explanation |
|---|---|
ADD |
Adds time units (labeled durations) to a given DB2 time stamp and returns a Natural time variable and a new DB2 time stamp. |
CNT2 |
Converts a Natural time variable (format T) into a DB2 time
stamp (column type TIMESTAMP) and labeled durations.
|
C2TN |
Converts a DB2 time stamp (column type TIMESTAMP)
into a Natural time variable (format T) and labeled durations.
|
DIFF |
Builds the difference between two given DB2 time stamps and returns labeled durations. |
GEN |
Generates a DB2 time stamp from the current date and time values
of the Natural system variable *TIMX
and returns a new DB2 time stamp.
|
SUB |
Subtracts labeled durations from a given DB2 time stamp and returns a Natural time variable and a new DB2 time stamp. |
TEST |
Tests a given DB2 time stamp for valid format and returns
TRUE or FALSE.
|
Note:
Labeled durations are units of year, month, day, hour, minute,
second and microsecond.
