Month: January 2017

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Dilbert 2017-01-12

Ruger has a winner on its hands with their American Rifle series. The guns are priced for value conscious shooters but punch above their weight with some fantastic features and…

The post New From Ruger: American Rimfire Target Model Rifles appeared first on The Truth About Guns.

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New From Ruger: American Rimfire Target Model Rifles

Last time we set up a connection from a PHP program to a MySQL server. This time we will progress a little further in that direction.

Query

Data is asked for from the MySQL server by using a query written in a language named Structured Query Language (SQL). Now that we have a connection open to the server, we can pass out request to the server.

Manual Labor

The PHP Manual is wonderful 99% of time. If you take a peek at the page for mysqli::query there is a great example of a simple query. Many of learned to program by copying/pasting from books/manuals and this is a great us of the examples in the PHP manual. Except it may not work for you.

MySQL is usually case SeNsATiVe, so ‘A’ may not be the same thing as ‘a’. But this is dependent to some extent on your operating system where ‘A’ = ‘a’. I was using the example from the manual and … it did not work.

What Happened

Here is an excerpt of the code, somewhat cut down:

<?php
$mysqli = new mysqli("localhost", "user", "secret", "world_x");

/* check connection */
if ($mysqli->connect_errno) {
    printf("Connect failed: %s\n", $mysqli->connect_error);
    exit();
}

$mysqli->close();
?>

Run the program and … nothing.

So What Happened?

What happened is a subtle problem that novices will smack into very hard. Take a look at this section of the example.

/* Select queries return a resultset */
if ($result = $mysqli->query("SELECT Name FROM City LIMIT 10")) {
    printf("Select returned %d rows.\n", $result->num_rows);

    /* free result set */
    $result->close();
}

If you try the query SELECT Name FROM City LIMIT 10; with the MySQL command line client program you will get the answer. And the answer is:

mysql> SELECT Name FROM City LIMIT 10;
ERROR 1146 (42S02): Table 'world_x.City' doesn't exist
mysql>

I am using the new world_x example database where the city is NOT capitalized instead of the old world database where it is! This lesson can be summed as check you schema/table/column names for case sensitivity. Except that there is another problem here.

In the real world occasional the database/table/column that you carefully double checked was spelled correctly and with the proper case sensitivity will go away. It may have been renamed, deleted, munged, or what have you. What is needed is a way to check to see if there was an error if the query can not run.

Lets change the code slightly:

/* Select queries return a resultset */
if ($result = $mysqli->query("SELECT Name FROM City LIMIT 10")) {
 printf("Select returned %d rows.\n", $result->num_rows);

 /* free result set */
 $result->close();
} else {
 printf("Query failed: %s\n", $mysqli->error);
}

Always Check for Return Codes

By simply adding about 40 characters, the reliability of the program shoots up immensely AND we get an exact answer if what went wrong.

Query failed: Table 'world_x.City' doesn't exist

Same error as when we tried by query by hand. But now our code can handle this issue. We could even try to catch the error, send a note via a message queue to the operations staff about the nature of the problem, and possible limp along until things are resolved. Or we could just call exit()

When you are offered a return code be sure to check it. Yes, it may be over kill in simple examples. But the payoff comes when things go bad and you are scrambling to find out eleven months from now why your program is suddenly not working.
via Planet MySQL
PHP and MySQL Basics II – Case Sense

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Screen Junkies digs 30 years into the vaults to pay tribute to one of our all-time favorites. It’s got adventure, dark humor, romance, and a wealth of memorable characters and lines we still quote to this day. Also, we felt exactly like Fred Savage as the story unfolded.

via The Awesomer
Honest Princess Bride Trailer

PHP and MySQL have had a long intertwined path together. I have been talking with a lot of newbies in the past several months who are trying to become PHP developers but are amazed at all the ancillary parts that go along with PHP such as unit testing, databases, JavaScript, continuous integration, and much more. Add in that there are two MySQL APIs — PDO & MySQLi — and an older deprecated mysql API still often found in the wild. This blog is the start of a series for new PHP developers to learn to program with a database.

Client Server Model

The PHP code when it seeks to talk to a MySQL (or most other databases) will make a connection to a port at an IP address. Usually MySQL is listening on port 3306. If you are developing an accessing a database on your local computer the IP address used will generally be at 127.0.0.1. The software that goes between the PHP application and the database is called a connector.

So your code on you local system an be talking to a database server on your local system or through a network connection. It does not matter which.

Can’t connect to MySQL server on ‘x.x.x.x’ (111)

The Can’t connect error can be especially frustrating. An experienced developer will know what to check from tears of experience. But this is a column on basics so we need to spell out the steps.

1. Is the IP address correct? It is easy to fat finger IP address and ironically 127.0.01 on many Linux boxes will connect up to 127.0.0.1.
2. Is there a instance of MySQL running at that IP address?
3. Is that instance listening on the generic port 3306? Is may be running someplace else and you will have to chance down that port number.
4. Can the MySQL command line shell or other tool connect to the instance? MySQL Workbench, PhPMyAdmin, the cli tools, and everything else authenticate through the same steps so if they work and your PHP program does not then most likely the fault is in the PHP code.

Setting up the client server connection

The PHP Manual is worth its weight in gold and you should refer to it often. Its examples are clear, or usually as clear as can be, and concise. Below is an excerpt example from the manual.

<?php

$mysqli = new mysqli("127.0.0.1", "user", "password", "database", 3306);
if ($mysqli->connect_errno) {
 echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
}

echo $mysqli->host_info . "\n";
?>

Note that the IP address, user name of "user", password of "password", and the port of 3306 will need to be changed to fit the installation. The mysqli call sets up the connection between the application and the MySQL database server.

Please note that you should protect usernames and password or any other information that could allow someone to compromise the server and data.

The if statement is invoked when there is an error code is returned from the $mysql->connect_errono call. Subsequently the error message from the server can be printed out using $mysqli->error. The error message itself can be terse but often points out what is wrong in the code.

Bad arguments

What follows below are three bad connection strings.

// Bad IP address
$mysqli = new mysqli("19.10.0.3", "root", "barfoo", "world_x", 3306);
if ($mysqli->connect_errno) {
 echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
}

// Bad account information
$mysqli = new mysqli("127.0.0.1", "root", "foobar", "world_x", 3306);
if ($mysqli->connect_errno) {
 echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
}

// Bad database specified
$mysqli = new mysqli("127.0.0.1", "root", "foobar", "world_xx\", 3306);
if ($mysqli->connect_errno) {
 echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
}

Part of mastering any computer programming language is learning to understand the error messages. The three examples above return similar but distinctly different messages.

The first of the trip provides the following error:

PHP Warning:  mysqli::__construct(): (HY000/2002): Network is unreachable in /home/dstokes/php/m02.php 
Failed to connect to MySQL: (2002) Network is unreachable

It would be nice to get more information than ‘Network in unreachable’ but it provides a starting point to diagnose the problem. Generally the more specific the problem, the more specific the error message.

The third of the trio attempts to connect to a database named ‘world_xx’ when we really wanted ‘world_x’.

PHP Warning: mysqli::__construct(): (HY000/1049): Unknown database 'world_xx' in /home/dstokes/php/m02.php
Failed to connect to MySQL: (1049) Unknown database 'world_xx'

Sadly for beginners it takes time and experience to get to the point where you can instantly look at an error and know what has gone wrong (or have a pretty good idea of what has gone wrong). But do not worry as many of us learn by correcting OUR mistakes and learning not to repeat them.

Connection Good

So after establishing a good connection to the MySQL server, we can now query it for data.

Next Time — what happened to my query??

via Planet MySQL
PHP and MySQL Basics

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Designer Daniel Ballou and Dashdot are working on this cool DIY audio system which lets you take ordinary cinder blocks and turn them into speakers. Apparently, the concrete minimizes vibration and coloration of sound. Ballou hopes to retail the kit for about $150.

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Cinder Speakers

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The Best 6 Sites to Get Free Ebooks

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An old segment from How It’s Made which shows how a steel rod is gradually made thinner and thinner, then run through a metal shaving machine, and woven together to transform it into the scrubby cleaning material we’re familiar with.

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How Steel Wool Is Made

Usually the chassis of a silencer is wasted space. No sights, no lasers, nothing but a chamber designed to contain and cool expanding gasses before they’re released from the muzzle….

The post Silencer Review: Alpha Dog Silencer appeared first on The Truth About Guns.

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Silencer Review: Alpha Dog Silencer

By David Codrea

USA – -(Ammoland.com)- Lessons learned from one man’s struggle to challenge a gun purchase denial from the National Instant Check System give insights into how difficult it can be for a citizen to clear his name once the government has decided he’s a “prohibited person.” Fortunately, an Anchorage medical professional and “avid gun collector” [name withheld at his request] had the savvy, the wherewithal and the persistence to successfully fight a bureaucratic denial of his right to arms.

A former U.S. Army officer with a clean record that includes not so much as a speeding ticket in the past 10 years, albeit with one inadvertent self-reported fish and game violation in 2004, the doctor attempted to purchase a rifle at Cabela’s in Anchorage Alaska in early November. His first background check was delayed and then it was denied a few days later.

As an aside, the doctor says he has purchased many firearms over the last decade with no trouble. He immediately filed an appeal letter online and after multiple tries at trying to reach a live human, got a recording saying FBI was currently evaluating appeals from August 2015, putting them one year and three months behind even looking at his appeal.

“This was unreasonable,” he noted with extreme understatement, “so I created a plan to expedite my appeal. I immediately filled out my appeal online when I received the denial.

“I contacted my congressman, Don Young, and his office sent a congressional inquiry to the FBI NICS,” the doctor continued. “And I completed my concealed carry course and turned in all the needed information to the background evaluation officer at the Alaska State Troopers. This agent evaluates your finger prints and other data to determine if you are eligible for your CCW permit. This agent also communicates with the FBI NICS.

“I sent another copy of my finger prints to NICS for evaluation,” he concluded. The end result was that the denial was overturned. The process took about four weeks vs. a year-and-a-half, but it required significant effort on my part.”

And the reason for the initial denial, for withholding a fundamental right for an undetermined period and without due process, and for making a citizen go through extraordinary measures, including recruiting the assistance of a United States Congressman in order to not get hung out to dry by a bureaucratic snafu?

“The fingerprints you submitted are not identical with those in a record used in the evaluation of your attempt to possess or receive a firearm,” a weasel-worded Department of Justice attempt at excuse-making without admitting fault (or heaven forbid apologizing for rejecting the wrong guy) offered as justification. “Based on further review and investigation, we have been able to determine you are eligible to possess or receive a firearm. The FBI Criminal Justice Information Services (CJIS) Division’s NICS Section Firearm Appeal Certificate is enclosed.

“If more than 30 days have elapsed since the initial background check, the FBI must recheck the NICS before allowing the firearm transfer,” the letter warned.

They had.

Reading about how bureaucratically rigid and wrong the government can be may make for forehead-slapping and head-shaking, but to a person trapped in their errors, it’s no laughing matter.  As Martin Luther King Jr. observed, “A right delayed is a right denied,” and that’s not supposed to happen under our Constitution without due process.

Researcher John Lott has documented the preponderance of “false positives” in his warnings against Brady background checks. That’s also a real danger in the latest bit of “bipartisan” rights denial being pushed under the “No Fly/No Buy” slogan. And it shows yet another downside to the Bloomberg “background check” mandates designed to end all private sales plus establish identifying data needed for a registration system (“Effectiveness depends on the ability to reduce straw purchasing, requiring gun registration…” — National Institute of Justice).

As noted, had this doctor been a person of lesser drive, someone who did not know how to go about righting a wrong and staying with it to completion, he’d still be in limbo. And there’s no guarantee the bureaucrats would make things right when they finally got around to trying to undo the sloppy work that led to the denial in the first place.

About David Codrea:

David Codrea is the winner of multiple journalist awards for investigating / defending the RKBA and a long-time gun rights advocate who defiantly challenges the folly of citizen disarmament.

In addition to being a field editor/columnist at GUNS Magazine and associate editor for Oath Keepers, he blogs at “The War on Guns: Notes from the Resistance,” and posts on Twitter: @dcodrea and Facebook.

This post Citizen Persistence after NICS Gun Purchase Block Results in Overturn of Denial appeared first on AmmoLand.com Shooting Sports News .

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Citizen Persistence after NICS Gun Purchase Block Results in Overturn of Denial