db.c

bonddb 是一个源于PostgreSQL封装包的对象。它是一个由C/C++编写的快速数据提取层应用软件

         break;
         }
      }
   if (row == -1)
      {
      db_moveto(obj, oldrow);
      debugmsg("Unable to find a record with the value selected");
      return -3;
      }

   /* set to the new postion like */
   db_moveto(obj, row);
   return 0;
   }

/**
 * db_deleteobject:
 * @obj: database object
 *
 * Deletes the record in obj, and all records which follow this one.  It only deletes the row your in, not the entire record set.
 * Needs to be tested still, as it has the potential to cause huge damage, especially with
 * things like circular relationships.
 *
 * Returns: non-zero on error
 */
gint
db_deleteobject(Object * obj)
{

	g_assert(obj);

	/* Run recusive delete, and move that code below into something else like
	 * db_obj_dodelete() */

	db_del_objectrecinit();
	db_del_objectrec(obj, db_id_get(obj));
	db_del_objectreccleanup();
	debugmsg("This is going to delete recusively.  TEST WELL BEFORE USE!");

	return 0;
   }

/**
 * db_clearobject:
 * @obj: database object
 *
 * Clear the contents of an object making everything blank.  This will free up any
 * record sets associated with @obj and setup the object as a new record.  The
 * table it points to will be the same as its existing table.
 *
 * Returns: non-zero on error
 */
gint
db_clearobject(Object * obj)
   {
   if (obj == NULL)
      return -3;
   return db_obj_clear(obj);
   }

/* CODE GRAVE YARD .... from db_getvalue*/

/* check to see if num is out of range. If so return "" string */

/*	if (obj->append == TRUE)
		{
		if (obj->row == obj->num-1)
			{
			warningmsg("Trying to extract a value from a not added object (in process of append");
			*retval = emptystring;
			return 0;
			}
		} */

/* data has changed so reload query. I disabled this cause i dont know why i have it */

/*   if (obj->changed == TRUE)// && obj->append != TRUE)
	db_refreshobject(obj);  */

/*   if ((fieldpos = db_getfieldpos(obj, field)) == -1)
      {
      errormsg("field %s not found in %s", field, obj->table->name);
      g_assert(NULL);	
      return -1;
      } */

/*	printf(":%d:%d  %s\n",obj->row,fieldpos,*retval); */

/* message("Got value %s for row %d, %d items in total, This is all strange and lovely and i think we ar egoing to be hit by a giant rock from outta space",*retval,obj->row,obj->num); */

/* new record, get what you just wrote */

/* if (obj->pg_oid > 0 && obj->res == NULL) { warningmsg("This is untested code. I dont know why i am here. HELP");
   db_refreshwrittenobject(obj); } 
10 PRINT "HELLO WORLD"
20 GOTO 10
	*/

/* check the local pointer */

/*   if (db_isnewrecord(objlocal) == TRUE && db_ischanged(objlocal) == FALSE)
      {
      errormsg("%s is a new record, I can't load values from it into the other object.\n"
					"You need to add some text",objlocal->name);
      return -1;
      } */

/*   if (db_isvalidforread(objlocal) == FALSE)
      {
      errormsg("Invalid oid for current record");
      return -4;
      } */

/*   desttable = objdest->table;
   g_assert(desttable);
   if (desttable->cref == NULL)
      {
      errormsg("Unable to find any relationships for this destionation table, can not proceed");
      return -5;
      }
 
   walk = g_list_first(desttable->cref);
   while (walk != NULL)
      {
      c = walk->data;
      g_assert(c);
      localfield = NULL;
      destfield = NULL;
      if (strcasecmp(c->table[0], objlocal->table->name) == 0 && c->casual == 0)
         {
         localfield = c->column[0];
         destfield = c->column[1];
         }
      else if (strcasecmp(c->table[1], objlocal->table->name) == 0 && c->casual == 0)
         {
         localfield = c->column[1];
         destfield = c->column[0];
         }
      if (localfield != NULL && destfield != NULL)
         {
         db_getfieldstr(objlocal, localfield, &value);
         db_addwrite(objdest, destfield, value);
         objdest->changed = FALSE;
         }
      walk = walk->next;
      }
   objdest->changed = FALSE;
 
   return 0;
   }
*/

/* Check to work if refreshnwrittenrecord worked. */

/* if (obj->res == NULL) { errormsg("Object result is null, meaning you trying to read stuff not yet written.\n"
   "This occured for %s.%s", obj->table->name, field); g_assert(NULL); } */

/* this code died somewhere else but we bury him here just the same */

/* if (c->obj != NULL) if (obj != c->obj || (obj == c->obj && c->pg_oid != obj->pg_oid)) db_flushobjects(); */

/* gchar *str; gint fieldpos; extern DbWriteCache *globaldbwritecache;
   errormsg("Code is obsolete. Do not use"); g_assert(NULL);
   g_assert(obj); if (globaldbwritecache != NULL) if (globaldbwritecache->obj != NULL) if (obj ==
   globaldbwritecache->obj) db_flushobjects();
   g_assert(obj->res); g_assert(obj->table); if (obj->res == NULL || obj->row < 0) { errormsg("obj->res is null or
   obj->row is < 0, i can't do this. arr"); return -3; }
   if (obj->append == TRUE) { if (obj->row == obj->num - 1) { (*retval) = 0; return 0; } }
   if ((fieldpos = db_getfieldpos(obj, field)) == -1) { errormsg("field not found"); return -1; } str = (gchar *)
   db_dbgetvalue(obj->res, obj->row, fieldpos); if (str == NULL) { errormsg("returned null"); return -2; } *retval =
   atoi(str); return 0; */

/**
  * db_getfieldint:
  * @obj: Database object
  * @field: database field name
  * @retval: int to return
  * Retreives an int from the database based on a object and field.
  * db_getfieldstr().
  * Returns: <b>error code</B> on how successful it was. 
  */

/*
gint
db_getfieldint(Object * obj, gchar * field, gint * retval)
   {
	
	
   gchar *str = NULL;
	*retval = 0;
   db_getfieldstr(obj, field, &str);
	if(str==NULL)
		{
		errormsg("Unable to get int value for field %s in %s",field,obj->name);
		if (db_isnewrecord(obj)==TRUE)
			g_assert(NULL);
		g_assert(NULL);
		return -1;
		}
   *retval = atoi(str);
   return 0;
   } */

/* Note, dont free the returned string from this, as its been used
   by something else. Soo NOOO YOUR NOT ALLOWED TO!. Hands off or else
   I'll poke you with nasty bits.
*/

/**
 * db_lookthroughobject:
 * @objlocal:
 * @othertable:
 * HMMM I"M DUMPING THIS CODE CAUSE IT AN"T USED MUCH 
 * Returns: %NULL on unable to find anything else the field that links it.
 */ /*
   gchar *
   db_lookthroughobject(Object * objlocal, gchar * othertable)
   {
   gchar *destfield, *localfield;
   GList *walk;
   DbTableDef *db;
   DbConstraintDef *c;
 
   g_assert(objlocal);
   g_assert(othertable);
 
   if (db == NULL)
   {
   debugmsg("No object found");
   return NULL;
   }
   db = db_findtable(othertable);
   walk = g_list_first(db->cref);
   while (walk != NULL)
   {
   c = walk->data;
   g_assert(c);
   if (strcasecmp(c->table[0], objlocal->table->name) == 0) */

/* othertable has a ref to local object */

/*         {
         localfield = c->column[0];
         destfield = c->column[1];
         return destfield;
         }
      else if (strcasecmp(c->table[1], objlocal->table->name) == 0)
         {
         localfield = c->column[1];
         destfield = c->column[0];
         return destfield;
         }
      walk = walk->next;
      }
   return NULL;
   } */ /*
   * db_getfieldstr:
   * obj: Data
 */

/*
gint
db_getfieldstr(Object * obj, gchar * field, gchar ** retval)
   {
   gint fieldpos;
 
   *retval = NULL;
   g_assert(obj);
*/

/* get field position in the data set */

/* if ((fieldpos = db_getfieldpos(obj, field)) == -1) { errormsg("field %s not found in %s", field, obj->name);
   return -1; } */

/* is the value sitting in the cache ready to be used ?? */

/* if (db_isincache(obj) == TRUE) if (globaldbwritecache->value[fieldpos] != NULL) { *retval =
   globaldbwritecache->value[fieldpos]; return 0; } */

/* do i need to flush the cache? */

/*   if (db_isflushneeded(obj) == TRUE)
      {
      debugmsg("Flushing cache cause its repeating stuff for query %s", obj->query);
      debugmsg("Gathering field %s, %d", field, obj->row);
      db_flushobjects();
      } */

/* am i allowed to read from this object ??. ie is not a blank record */

/*   if (db_isvalidforread(obj) == FALSE)
      {
      debugmsg("empty record, can not retrieve a value %s at postion %d of %d", field, obj->row, obj->num);
      return 1;
      }
 */

/* assumes row and field is set right, and res is correct */

/* The string is also stripped to not contain end trailing or beginning spaces. This shoulnd't create a memory leak,
   but you never know. I'll check for this later on */

/*	db_field_read(obj, field, retval);
   (*retval) = g_strstrip((gchar *)(*retval)); */

/* Something went straigly wrong */

/*   if (*retval == NULL)
      {
      errormsg("returned null");
      return -2;
      }
   return 0;
   }*/

/* Let there souls rest in peace ... */

/**
 * db_getobjectbyreference:
 * @obj: Database object
 * @tablename: Name of table to load object by
 *
 * This function will create a new database object based on an existing object
 * and a table name.  Constraint information will be used to work out how the
 * two tables relate to each other.
 */
Object *
db_getobjectbyreference(Object * obj, gchar * tablename)
   {
   g_assert(obj);
   g_assert(tablename);
   return db_mapme_findobjectbytable(obj, tablename);
   }

/**
 * db_numrows:
 * @obj: Database object
 *
 * Returns the number of rows there are in a object.
 *
 * Returns: interger number of rows in a object dataset
 */
gint
db_numrows(Object * obj)
   {
   g_assert(obj);
	return db_numrecord(obj);
   }

/**
 * db_addobjecttoobject:
 * @objdest: the new database object which will have information added to it
 * @objlocal: the existing base database object.
 * 
 * This is not a major api call, db_loadbyobject() will automatically call this
 * function.
 *
 * Elements of @objlocal will be used to create elements in @objdest.  This will
 * find all the links between the two objects and populate @objdest with 
 * values corresponding from those links.
 *
 * Returns: non-zero on error
 */

gint
db_addobjecttoobject(Object * destobj, Object * obj)
   {
   DbConstraintDef *cref;
   DbTableDef *desttabledef;
   DbBirth *birth;

   /* loading yourself by yourself. hmmm */
   if (strcmp(destobj->name, obj->name) == 0)
      {
      errormsg("Your trying to add yourself from yourself to yourself. confusing huh? well what about me");
      return -1;
      }
   desttabledef = db_findtable(destobj->name);
   g_assert(desttabledef);
   /* TODO: expand support to have more than one table source */
   cref = db_constraint_getonmatch(desttabledef->cref, obj->name, destobj->name, 0);
   if (cref == NULL)
      {
      errormsg("Unable to find a relationship between %s and %s, make sure a cref exists", obj->name, destobj->name);
      return -3;
      }

   /* now the sensible stuff */
   birth = db_birth_create(NULL, destobj->name);
   db_birth_applycref(obj, birth, cref);
   db_birth_save(destobj, birth);
   debugmsg("Spring Chickens!");
   db_birth_springchicken(destobj);
   return 0;
   }

/**
 * db_add:
 * @obj: Database object
 *
 * Adds another record onto the end of a database object.  For example if you
 * performaned an sql query to create a database object you can then use
 * this function to append a new record onto the end of that record set.
 * Default values will be applied and if it wsa an object loaded by
 * db_loadobjectbyobject() then other nessesary values will also
 * be added.
 *
 * Returns: non-zero on failure
 */
gint
db_add(Object * obj)
   {
   gint num, retval = 0;

   g_assert(obj);
   if (db_isabletoadd(obj) == FALSE || (db_isabletogetid(obj) == FALSE && obj->num > 0))
      {
      debugmsg("You can't add a record without finishing this record");
      return -1;
      }
   num = obj->num;
   /* add a new item to the cache */
   db_setforinsert(obj);
   retval -= db_moveto(obj, obj->num - 1);
   retval -= db_obj_applydefaults(obj);

   if (obj->birth != NULL)
		{
		debugmsg("Applying default sprintchicken values.");
      retval -= db_birth_springchicken(obj);
		}
   if (obj->num != num + 1)
      {
      errormsg("unable to add new record, orginally there was %d now there is %d.\n"
               "There should be one more", num, obj->num);
      }
   return retval;
   }

/**
* db_insert:
* @obj: Database object
*
* Not yet implimented
*
* Returns: non-zero on failure
*/
gint
db_insert(Object * obj)
   {
   g_assert(obj);

   errormsg("NOT WRITTEN. Please code this. : TODO");
   g_assert(NULL);

   if (db_isabletoadd(obj) == FALSE)
      {
      warningmsg("You can't add a record without finishing this record");
      return -1;
      }
   /* add a new item to the cache */
   /*TODO c = db_toliet_addtocache(obj); 
   c->origrow = obj->row + 1;
   obj->row = obj->row + 1;
   obj->num++;
   db_moveto(obj, obj->row + 1); */
   return 0;
   }

/**
 * db_createdeadobject:
 * @tablename: Name of a table where the record will be inserted
 *
 * Will create a non-usuable dead object.  This object can be used
 * to indicate what fields etc exist on the datasource @tablename.
 *
 * Returns: A newly created database object, or %NULL on error.
 */
Object*
db_createdeadobject(gchar *tablename)
	{
	Object *obj;

   obj = db_obj_create(tablename);
   obj->numfield = db_numfields(obj);
   db_obj_handle_empty_recordset(obj);

   return obj;
	}