Several Natural and non-Natural subprograms are available to provide you with either internal information from the Natural interface to SQL/DS or specific functions that are not available within the interface itself.
From within a Natural program, Natural subprograms are invoked with the CALLNAT statement and non-Natural subprograms are invoked with the CALL statement.
This section covers the following topics:
All Natural subprograms are provided in the library SYSSQL and should be copied to the SYSTEM or steplib library, or to any library where they are needed. The corresponding parameters must be defined by using either the DEFINE DATA statement in structured mode or the RESET statement in reporting mode.
The Natural subprograms NDBBRM, NDBDBR2, NDBDBR3 allow the optional specification of the database ID, file number, password and cipher code of the library file containing the program to be examined.
If these parameters are not specified, either the actual FNAT file or the FUSER file is used to locate the program to be examined depending on whether the library name begins with ‘SYS’ or the library name does not begin with ‘SYS’.
Programs invoking NDBBRM, NDBDBR2, NDBDBR3 without these Parameters will also work like before this change as the added parameters are declared as optional.
The following subprograms are provided:
Subprogram | Function |
---|---|
NDBDBRM
|
Checks whether a Natural program contains SQL access and whether it has been modified for static execution. |
NDBDBR2
|
Checks whether a Natural program contains SQL access and whether it has been modified for static execution. |
NDBDBR3
|
Checks whether a Natural program contains SQL access, whether it has been modified for static execution, and whether it can be generated as static. |
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 an SQL/DS TIMESTAMP column as an alphanumeric field and vice versa. |
The Natural subprogram NDBDBRM is used to check whether a Natural program contains SQL access and whether it has been modified for static execution. It is also used to obtain the corresponding package name from the header of a Natural program generated as static (see also Preparing Natural Programs for Static Execution).
A sample program called CALLDBRM is provided on the installation tape; it demonstrates how to invoke NDBDBRM. A description of the call format and of the parameters is provided in the text member NDBDBRMT.
The calling Natural program must use the following syntax:
The calling Natural program must use the following syntax:
CALLNAT 'NDBDBRM' #LIB #MEM #DBRM #RESP #DBID #FILENR #PASSWORD #CIPHER
The various parameters are described in the following table:
Parameter | Format/Length | Explanation |
---|---|---|
#LIB |
A8 | Contains the name of the library of the program to be checked. |
#MEM |
A8 | Contains the name of the program (member) to be checked |
#DBRM |
A8 | Returns the DBRM name. |
#RESP |
I2 | Returns a response code. The possible codes are listed below. |
#DBID |
N5 | Optional, Database ID of library file. |
#FILENR |
N5 | Optional, File number of library file. |
#PASSWORD |
A8 | Optional, Password of library file. |
#CIPHER |
N8 | Optional, Cipher code of library file. |
The #RESP parameter can contain the following response codes:
Code | Explanation |
---|---|
0 | The member #MEM in library #LIB has SQL access; it is static if #DBRM contains a value. |
-1 | The member #MEM in library #LIB has no SQL access. |
-2 | The member #MEM in library #LIB does not exist. |
-3 | No library name has been specified. |
-4 | No member name has been specified. |
-5 | The library name must start with a letter. |
<-5 | Further negative response codes correspond to error numbers of Natural error messages. |
> 0 | Positive response codes correspond to error numbers of Natural Security messages. |
The Natural subprogram NDBDBR2 is used to check whether a Natural program contains SQL access and whether it has been modified for static execution. It is also used to obtain the corresponding DBRM name from the header of a Natural program generated as static (see also Preparing Natural Programs for Static Execution) and the time stamp generated by the precompiler.
A sample program called CALLDBR2 is provided on the installation tape; it demonstrates how to invoke NDBDBR2. A description of the call format and of the parameters is provided in the text member NDBDBR2T.
The calling Natural program must use the following syntax:
CALLNAT 'NDBDBR2' #LIB #MEM #DBRM #TIMESTAMP #PCUSER #PCRELLEV #ISOLLEVL #DATEFORM #TIMEFORM #RESP #DBID #FILENR #PASSWORD #CIPHER
The various parameters are described in the following table:
Parameter | Format/Length | Explanation |
---|---|---|
#LIB |
A8 | Contains the name of the library of the program to be checked. |
#MEM |
A8 | Contains the name of the program (member) to be checked |
#DBRM |
A8 | Returns the DBRM name. |
#TIMESTAMP |
B8 | Consistency token generated by precompiler |
#PCUSER |
A1 | User ID used at precomplile (only SQL/DS) |
#PCRELLEV |
A1 | Release level of precompiler (only SQL/DS) |
#ISOLLEVL |
A1 | Precomplier isolation level (only SQL/DS) |
#DATEFORM |
A1 | Date format (only SQL/DS) |
#TIMEFORM |
A1 | Time format (only SQL/DS) |
#RESP |
I2 | Returns a response code. The possible codes are listed below. |
#DBID |
N5 | Optional, Database ID of library file. |
#FILENR |
N5 | Optional, File number of library file. |
#PASSWORD |
A8 | Optional, Password of library file. |
#CIPHER |
N8 | Optional, Cipher code of library file. |
The #RESP parameter can contain the following response codes:
Code | Explanation |
---|---|
0 | The member #MEM in library #LIB has SQL access; it is static if #DBR2 contains a value. |
-1 | The member #MEM in library #LIB has no SQL access. |
-2 | The member #MEM in library #LIB does not exist. |
-3 | No library name has been specified. |
-4 | No member name has been specified. |
-5 | The library name must start with a letter. |
<-5 | Further negative response codes correspond to error numbers of Natural error messages. |
> 0 | Positive response codes correspond to error numbers of Natural Security messages. |
The Natural subprogram NDBDBR3 is used to check whether a Natural program contains SQL access (#RESP 0), whether the Natural program contains solely SQL statements, which are dynamically executable (#RESP 0, #DBRM '*DYNAMIC') and whether it has been modified for static execution (#RESP 0, #DBRM dbrmname). It is also used to obtain the corresponding DBRM name from the header of a Natural program generated as static (see also Preparing Programs for Static Execution) and the time stamp generated by the precompiler.
A sample program called CALLDBR3 is provided on the installation tape; it demonstrates how to invoke NDBDBR3. A description of the call format and of the parameters is provided in the text member NDBDBR3T.
The calling Natural program must use the following syntax:
CALLNAT 'NDBDBR3' #LIB #MEM #DBRM #TIMESTAMP #PCUSER #PCRELLEV #ISOLLEVL #DATEFORM #TIMEFORM #RESP #DBID #FILENR #PASSWORD #CIPHER
The various parameters are described in the following table:
Parameter | Format/Length | Explanation |
---|---|---|
#LIB |
A8 | Contains the name of the library of the program to be checked. |
#MEM |
A8 | Contains the name of the program (member) to be checked |
#DBRM |
A8 |
Returns the DBRM name.
|
#TIMESTAMP |
B8 | Consistency token generated by precompiler |
#PCUSER |
A1 | User ID used at precomplile (only SQL/DS) |
#PCRELLEV |
A1 | Release level of precompiler (only SQL/DS) |
#ISOLLEVL |
A1 | Precomplier isolation level (only SQL/DS) |
#DATEFORM |
A1 | Date format (only SQL/DS) |
#TIMEFORM |
A1 | Time format (only SQL/DS) |
#RESP |
I2 | Returns a response code. The possible codes are listed below. |
#DBID |
N5 | Optional, Database ID of library file. |
#FILENR |
N5 | Optional, File number of library file. |
#PASSWORD |
A8 | Optional, Password of library file. |
#CIPHER |
N8 | Optional, Cipher code of library file. |
The #RESP parameter can contain the following response codes:
Code | Explanation |
---|---|
0 |
The member #MEM in library #LIB has SQL access; it is static, if #DBRM contains a value other than space and *DYNAMIC. |
-1 | The member #MEM in library #LIB has no SQL access. |
-2 | The member #MEM in library #LIB does not exist. |
-3 | No library name has been specified. |
-4 | No member name has been specified. |
-5 | The library name must start with a letter. |
<-5 | Further negative response codes correspond to error numbers of Natural error messages. |
> 0 | Positive response codes correspond to error numbers of Natural Security messages. |
The Natural subprogram NDBERR replaces the "E" function 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); see also Error Handling.
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 SQL/DS access. |
DBTYPE |
B1 | Returns the identifier (in hexadecimal format) for the currently used database (where X'03' identifies SQL/DS). |
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 Adabas SQL Server documentation) 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). |
Valid functions for the #FUNCTION parameter are:
Function | Parameter | Explanation |
---|---|---|
CLOSE |
Closes the cursor for the SELECT statement. | |
EXECUTE |
|
Executes the SQL statement. |
Contains the length of the statement. | ||
Contains the SQL statement. The first two characters must be blank. | ||
FETCH |
|
Returns a record from the SELECT statement. |
Size of #TEXT (in bytes).
|
||
Buffer for the record. | ||
TITLE |
|
Returns the header for the SELECT statement. |
Size of #TEXT (in bytes); receives the length of the header (= length of the record). | ||
Buffer for the header line. |
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; probably invalid call sequence or statement other than SELECT. |
-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.
Notes:
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; see also Error Handling.
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 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 the 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 "-1" indicates that all rows of a table in a segmented tablespace have been deleted; see also *NUMBER.
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 rows affected.
For SQL/DS, Natural provides a TIMESTAMP column as an alphanumeric field (A26) of the format "YYYY-MM-DD-HH.MM.SS.MMMMMM"; see also List Columns of an SQL Table.
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 SQL/DS time stamps and vice versa, and performs SQL/DS time stamp arithmetics.
A sample program called CALLSTMP is provided on the installation tape which 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 SQL/DS time stamp and returns a Natural time variable and a new SQL/DS time stamp. |
CNT2 |
Converts a Natural time variable (format T) into an SQL/DS time stamp (column type TIMESTAMP) and labeled durations. |
C2TN |
Converts an SQL/DS time stamp (column type TIMESTAMP) into a Natural time variable (format T) and labeled durations. |
DIFF |
Builds the difference between two given SQL/DS time stamps and returns labeled durations. |
GEN |
Generates an SQL/DS time stamp from the current date and time values of the Natural system variable *TIMX and returns a new SQL/DS time stamp. |
SUB |
Subtracts labeled durations from a given SQL/DS time stamp and returns a Natural time variable and a new SQL/DS time stamp. |
TEST |
Tests a given SQL/DS time stamp for valid format and returns "TRUE" or "FALSE". |
Note:
Labeled durations are units of year, month, day, hour, minute,
second and microsecond.
DB2SERV is an Assembler program entry point which can be called from within a Natural program.
DB2SERV performs either of the following functions:
Function "D", which performs the SQL statement EXECUTE IMMEDIATE;
Function "U", which calls the database connection services (z/VSE batch mode only).
The parameter or variable values returned by each of these functions are checked for their format, length and number.
Function "D" performs the SQL statement EXECUTE IMMEDIATE. This allows SQL statements to be issued from within a Natural program.
The SQL statement string that follows the EXECUTE IMMEDIATE statement must be assigned to the Natural program variable STMT. It must contain valid SQL statements allowed with the EXECUTE IMMEDIATE statement as described in the relevant IBM documentation. Examples can be found below and in the demonstration programs DEM2* in library SYSSQL.
Note:
The conditions that apply to issuing Natural
END TRANSACTION or
BACKOUT TRANSACTION statements
also apply when issuing SQL
COMMIT or ROLLBACK
statements.
CALL 'DB2SERV' 'D' STMT STMTL SQLCA RETCODE
The variables used in this command are described in the following table:
Variable | Format/Length | Explanation | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
STMT |
Annn | Contains a command string which consists of SQL syntax as described above. | ||||||||
STMTL |
I2 | Contains the length of the string defined in STMT. | ||||||||
SQLCA |
A136 | Returns the current contents of the SQL communication area. | ||||||||
RETCODE |
I2 |
Returns an interface return code. The following codes are possible:
|
The current contents of the SQLCA and an interface return code (RETCODE) are returned. The SQLCA is a collection of variables that are used by SQL/DS to provide an application program with information on the execution of its SQL statements.
The following example shows you how to use DB2SERV with function "D":
************************************************************************** * DEM2CREA - CREATE TABLE NAT.DEMO * ************************************************************************** * DEFINE DATA LOCAL USING DEMSQLCA LOCAL * Parameters for DB2SERV 1 STMT (A250) 1 STMTL (I2) CONST <250> 1 RETCODE (I2) * END-DEFINE * COMPRESS 'CREATE TABLE NAT.DEMO' '(NAME CHAR(20) NOT NULL,' ' ADDRESS VARCHAR(100) NOT NULL,' ' DATEOFBIRTH DATE NOT NULL,' ' SALARY DECIMAL(6,2),' ' REMARKS VARCHAR(500))' INTO STMT CALL 'DB2SERV' 'D' STMT STMTL SQLCA RETCODE * END TRANSACTION * IF RETCODE = 0 WRITE 'Table NAT.DEMO created' ELSE FETCH 'SQLERR' END-IF END **************************************************************************
Note:
The functionality of the DB2SERV function "D" is also
provided with the PROCESS
SQL statement (see also the section
SQL Statements in the Natural
Statements documentation).
Function "U" calls the database connection services when running in batch mode under z/VSE; see also Sample Batch Verification Job (z/VSE only).
The user ID and password for the connection to SQL/DS must be assigned to the Natural program variables USER-ID and PASSWORD, respectively. An interface return code (RETCODE) is returned.
CALL 'DB2SERV' 'U' USER-ID PASSWORD RETCODE
The variables used in this command are described in the following table:
Variable | Format/Length | Explanation | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
USER-ID |
A8 | A Natural variable that contains the user ID for the connection to SQL/DS. | ||||||||
PASSWORD |
A8 | A Natural variable that contains the user password for the connection to SQL/DS. | ||||||||
RETCODE |
I2 |
A Natural variable that returns an interface return code. The following codes are possible:
|