dbnpdefine

Define a notification procedure.

RETCODE dbnpdefine(dbproc, procedure_name, namelen)
 
DBPROCESS     *dbproc;
DBCHAR            *procedure_name;
DBSMALLINT     namelen;

dbproc: A pointer to the DBPROCESS structure that provides the connection for a particular front-end/server process. It contains all the information that DB-Library/C uses to manage communications and data between the front end and the server.

procedure_name: A pointer to the name of the notification procedure being defined.

namelen: The length of procedure_name, in bytes. If procedure_name is null-terminated, pass namelen as DBNULLTERM.

SUCCEED or FAIL.

dbnpdefine defines a notification procedure. Defining a notification procedure is the first step in creating it.
A notification procedure is a special type of Open Server registered procedure. A notification procedure differs from a normal Open Server registered procedure in that it contains no executable statements. Notification procedures are the only type of Open Server registered procedure that a DB-Library/C application can create.
To create a notification procedure, a DB-Library/C application must:
- Define the procedure using dbnpdefine
- Describe the procedure’s parameters, if any, using dbregparam
- Create the procedure using dbnpcreate
All DB-Library/C routines that apply to registered procedures apply to notification procedures as well. For example, dbregexec executes a registered procedure, which may or may not be a notification procedure. Likewise, dbreglist lists all registered procedures currently defined in Open Server, some of which may be notification procedures.

This is an example of defining a notification procedure:

 DBPROCESS    *dbproc;

 DBINT        status;

/*

 ** Let’s create a notification procedure called

 ** "message" which has two parameters:

 **     msg     varchar(255)

 **     userid  int

*/

/*

 ** Define the name of the notification procedure

 ** "message"

*/

 dbnpdefine (dbproc, "message", DBNULLTERM);

 /* The notification procedure has two parameters:

 **     msg    varchar(255)

 **     userid int

 ** So, define these parameters.  Note that

 ** neither of the parameters is defined with a

 ** default value.

*/

 dbregparam (dbproc, "msg", SYBVARCHAR,

      DBNODEFAULT, NULL);

 dbregparam (dbproc, "userid", SYBINT4,

      DBNODEFAULT, 4);

/*  Create the notification procedure: */

 status = dbnpcreate (dbproc);

 if (status == FAIL)

      fprintf(stderr, "ERROR:  Failed to create \

        message!\n");

 else

      fprintf(stdout, "Success in creating \

        message!\n");