Dbxrmvkey()

From Recital Documentation Wiki
Revision as of 10:34, 6 May 2009 by Yvonnemilne (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

PURPOSE

remove key from all tags in tagged index file


SYNOPSIS

#include "dbl.h"
 
	int	dbxrmvkey(dbx, key, recno)
 
	<input parameters>
	char	*dbx;		/* Tagged index file descriptor	*/
	char	*key;		/* Address of a buffer containing the key to be removed */
	long	recno;		/* Record number associated with key to be removed */
 
 
	<output parameters>
	none


RETURN VALUE

The dbxrmvkey() function returns 0 for success, or < 0 if an error occurs. See the section on return code values for a detailed list of return codes.

DESCRIPTION

The dbxrmvkey() function searches for the specified key in the active tag, and then removes all keys in the tagged index file, .DBX, for the matching record number.


EXAMPLE

The following example creates the shipwreck table and tags on the VESSEL and FLAG fields. It appends a record, adds the key, then removes and updates the key.


#include <stdio.h>
#include "dbl.h"			/* Recital/Library include file */
#include "dblproto.h"		/* Recital/Library prototype file */
 
	static	dBFIELD fields[6] = {
		"VESSEL",	'C',	18,	0,	0,
		"LAT",	'N',	4,	1,	0,
		"LONG",	'N',	4,	1,	0,
		"AMOUNT",	'N',	10,	0,	0,
		"DATE",	'D',	8,	0,	0,
		"FLAG",	'C',	9,	0,	0
	};
 
	static void errorproc(
		char	*func,
		char	*str,
		int	rc);
 
	static char *text_table[] =  {
		"Santa Margarita   80.027.5   700000095/01/01Spanish  "
	};
 
	main()
	{
		int		rc; 			/* Return Code for error handling */
		char		*dbf; 		/* File descriptor for table */
		char		*dbx; 		/* File descriptor for tagged index */
		FLDNUM	fieldcount;		/* Number of fields to create */
		int		i;	 		/* Loop control variable */
		long		recno; 		/* Table record variable */
 
		rc = dbdcache(100);
		errorproc("dbdcache()","table cache specified.", rc);
		rc = dbicache(100);
		errorproc("dbicache()", "index cache specified.",rc);
		rc = dbfilemode(0,0);
 
		fieldcount = 6;
 
		rc = dbcreat("shipwreck.dbf",fieldcount, fields);
		errorproc("dbcreat()","database created.", rc);
 
		rc = dbopen("shipwreck.dbf", &dbf);
		errorproc("dbopen()","table opened.", rc);
 
		rc = dbxcreate( dbf,
			fields[0].fieldnm,		/* "VESSEL",  */
			&dbx,
			fields[0].fieldnm,		/* "VESSEL",  */
			NULL,
			0,
			0);
		errorproc("dbxcreate()","tag created", rc);
 
		rc = dbxcreate( dbf,
			fields[5].fieldnm,		/* "FLAG",  */
			&dbx,
			fields[5].fieldnm,		/* "FLAG",  */
			NULL,
			0,
			0);
		errorproc("dbxcreate()","tag created", rc);
		rc = dbxclose(dbx);
		errorproc("dbxclose()", "tagged index closed.", rc);
 
		rc = dbxopen(dbf, "shipwreck.dbx", &dbx);
		errorproc("dbxopen()","tagged index opened.", rc);
 
		rc = dbappend(dbf, text_table[0], &recno);
		errorproc("dbappend()", "record appended.", rc);
		rc = dbxakey(dbx, recno);
		errorproc("dbxakey()",  "key added.", rc);
 
		rc = dbflush(dbf);
		errorproc("dbflush()", "table cache flushed.", rc);
		rc = dbxflsh(dbx);
		errorproc("dbxflsh()", "tagged index cache flushed.", rc);
 
		rc = dbxrmvkey(dbx, "Santa Margarita   ", recno);
		errorproc("dbxrmvkey()", "key physically removed.", rc); 
 
		rc = dbxakey(dbx, recno);
		errorproc("dbxakey()",  "key added back in.", rc);
 
		rc = dbxupd(dbx, recno);
		errorproc("dbxupd()", "update key.", rc);
 
		rc = dbxclose(dbx);
		errorproc("dbxclose()", "tagged index closed.", rc);
		rc = dbclose(dbf);
		errorproc("dbclose()", "table closed.", rc);
 
		exit(0);
	}
 
	static void errorproc(func, str, rc)
	char	*func;
	char	*str;
	int	rc;
	{
		if ( rc != SUCCESS ) {
			printf("\n  Error performing function %s -> %d\n", func, rc);
		exit(1);
	}
	printf("Function: \t%s, \t%s - Ok\n", func, str);
	return;
}


SEE ALSO

dbxakey(), dbxupd()