サンプル・プログラム: ユーザー・イグジット

次の例にユーザー・イグジットを示します。

/**************************************************************
Sample Program 5:  SQL*Forms User Exit

This user exit concatenates form fields.  To call the user 
exit from a SQL*Forms trigger, use the syntax

   user_exit('CONCAT field1, field2, ..., result_field');

where user_exit is a packaged procedure supplied with SQL*Forms
and CONCAT is the name of the user exit.  A sample form named
CONCAT invokes the user exit.
**************************************************************/

#define min(a, b) ((a < b) ? a : b)
#include <stdio.h>
#include <string.h>

/* Include the SQL Communications Area, a structure through which
 * Oracle makes runtime status information such as error
 * codes, warning flags, and diagnostic text available to the
 * program.
 */
#include <sqlca.h>

/* All host variables used in embedded SQL in this example
 * appear in the Declare Section.
 */
EXEC SQL BEGIN DECLARE SECTION;
    VARCHAR   field[81];
    VARCHAR   value[81];
    VARCHAR   result[241];
EXEC SQL END DECLARE SECTION;


/* Define the user exit, called "concat". */
int concat(cmd, cmdlen, msg, msglen, query)
char *cmd;     /* command line in trigger step ("CONCAT...") */
int  *cmdlen;  /* length of command line */
char *msg;     /* trigger step failure message from form */
int  *msglen;  /* length of failure message */
int  *query;   /* TRUE if invoked by post-query trigger,
                  FALSE otherwise */
{
    char *cp = cmd + 7;    /* pointer to field list in
                              cmd string; 7 characters
                              are needed for "CONCAT " */
    char *fp = (char*)&field.arr[0];  /* pointer to a field name in
                                         cmd string */
    char  errmsg[81];      /* message returned to SQL*Forms
                              on error */
    int   errlen;          /* length of message returned
                              to SQL*Forms */

/* Branch to label sqlerror if an ORACLE error occurs. */
    EXEC SQL WHENEVER SQLERROR GOTO sqlerror;

    result.arr[0] = '\0';

/* Parse field names from cmd string. */
    for (; *cp != '\0'; cp++)
    {
       if (*cp != ',' && *cp != ' ')
           /* Copy a field name into field.arr from cmd. */
       {
           *fp = *cp;
           fp++;
       }
       else
           if (*cp == ' ')
           {   /* Have whole field name now. */
               *fp = '\0';
               field.len = strlen((char *) field.arr);
               /* Get field value from form. */
               EXEC TOOLS GET :field INTO :value;
               value.arr[value.len] = '\0';
               strcat((char *) result.arr, (char *) value.arr);
               fp = (char *)&field.arr[0];  /* Reset field pointer. */
           }
    }

/* Have last field name now. */
    *fp = '\0';
    field.len = strlen((char *) field.arr);
    result.len = strlen((char *) result.arr);

/* Put result into form. */
    EXEC TOOLS PUT :field VALUES (:result);

/* Trigger step succeeded. */
    return(IAPSUCC);

sqlerror:
    strcpy(errmsg, "CONCAT: ");
    strncat(errmsg, sqlca.sqlerrm.sqlerrmc, min(72,
        sqlca.sqlerrm.sqlerrml));
    errlen = strlen(errmsg);
/* Pass error message to SQL*Forms status line. */
     EXEC TOOLS MESSAGE :errmsg ;
    return(IAPFAIL);  /* Trigger step failed. */
}