iPhone: Sqlite update or insert row

I want to update the quantity if the menuid is already available otherwise add a new row. I used the following code.But no row is added or updated.

sqlite3 *database;

    sqlite3_stmt *addStmt=nil;

    if (selection== nil) {

        selection =@"Medium";

    }

if (sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) {



           const char *select="select quantity from item where menuid = ?";

            sqlite3_stmt *selectstmt;

            if(sqlite3_prepare_v2(database, select, -1, &selectstmt, NULL) == SQLITE_OK) {



                while(sqlite3_step(selectstmt) == SQLITE_ROW) {

                    menuID= [NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt, 0)];

                    char *quant = (char *)sqlite3_column_text(selectstmt,1);

                    quantity=[NSString stringWithUTF8String:(char *)quant];

                 //   [self.ids addObject:menuID]; 



                }

                sqlite3_reset(selectstmt);

            }

            NSString *quant=[NSString stringWithFormat:@"%@",quantity];





if (quant == @"") {

    if (addStmt == nil) {

          //   const char *sql = "delete from item";

            const char *sql = "insert into item(menuid,itemName,price,quantity,spiciness) Values( ?, ?, ?, ?,?)";



            if(sqlite3_prepare_v2(database, sql, -1, &addStmt, NULL) != SQLITE_OK)

                NSAssert1(0, @"Error while creating add statement. '%s'", sqlite3_errmsg(database));

        }

        // NSLog(@"ADDSTMT:%@",addStmt);

        sqlite3_bind_int(addStmt, 1, [itemId integerValue]);

        sqlite3_bind_text(addStmt, 2, [name UTF8String], -1, SQLITE_TRANSIENT);

        sqlite3_bind_double(addStmt, 3, [priceItem doubleValue]  );

        sqlite3_bind_int(addStmt, 4, number);

        sqlite3_bind_text(addStmt, 5, [selection UTF8String],-1,SQLITE_TRANSIENT);

        NSLog(@"Name:%@",name);

            NSLog(@"MENU IDe%@",priceItem);



        if(SQLITE_DONE != sqlite3_step(addStmt)){

            //  NSAssert1(0, @"Error while inserting data. '%s'", sqlite3_errmsg(database));

        }

        else

            //SQLite provides a method to get the last primary key inserted by using sqlite3_last_insert_rowid



            menuID = [NSDecimalNumber numberWithLongLong:sqlite3_last_insert_rowid(database)];



        //Reset the add statement.

        sqlite3_reset(addStmt);



}





else{

        if (addStmt == nil) {

            //   const char *sql = "delete from item";

            const char *sql = "update item set quantity= ? where menuid = ?";



            if(sqlite3_prepare_v2(database, sql, -1, &addStmt, NULL) != SQLITE_OK)

                NSAssert1(0, @"Error while creating add statement. '%s'", sqlite3_errmsg(database));

        }

        // NSLog(@"ADDSTMT:%@",addStmt);

        sqlite3_bind_int(addStmt, 2, [itemId integerValue]);

        number=number+[quant intValue];

        sqlite3_bind_int(addStmt, 1, number);



        NSLog(@"Name:%@",name);

        NSLog(@"MENU IDe%@",priceItem);



        if(SQLITE_DONE != sqlite3_step(addStmt)){

            //  NSAssert1(0, @"Error while inserting data. '%s'", sqlite3_errmsg(database));

        }

        else

            //SQLite provides a method to get the last primary key inserted by using sqlite3_last_insert_rowid



            menuID = [NSDecimalNumber numberWithLongLong:sqlite3_last_insert_rowid(database)];



        //Reset the add statement.

        sqlite3_reset(addStmt);







    sqlite3_close(database);



}

}