Passing variable from shell exec to mysql_query [duplicate] - php

This question already has answers here:
What is the difference between single-quoted and double-quoted strings in PHP?
(7 answers)
Closed 5 years ago.
I'm trying to read temperature from sensor DHT22 connected to raspberry pi and write it to mysql DB via PHP script.
I'm getting the temperature like this:
$temp = shell_exec('./temp.py');
Script returns number like 45 or 45.7 etc... The same as humidity.. When I echo it in the same script, it works.
And the thing, which I cannot pass through is here:
$sql='INSERT INTO values (id, date, time, timestamp, temp, hum) VALUES ("", NOW(), NOW(), NOW(), "$temp", "$hum")';
$result = MySQL_Query($sql);
But in DB is always written $temp and $hum, not the actual values. I think that I've already tried all possible combinations of quotation marks, etc...
What can be possibly wrong? Thanks in advance for the answers.

$sql="INSERT INTO values (id, date, time, timestamp, temp, hum) VALUES (\"\", NOW(), NOW(), NOW(), \"$temp\", \"$hum\")";
$result = MySQL_Query($sql);
Notice the double quotes.
There is a difference between double and single quotes:
Double quotes are parsed by the php engine. You can put variables inside them, and can be used to display escaped special characters.
Single quotes, on the other hands, are displayed as they are. They are not parsed by PHP and do not require escaping, except for the ' to tell the interpreter whether the quote is the end of the string or part of it.
You were using single quotes, that's why your string isn't parsed into variables.
Further information could be found in the PHP Manual

Related

Inputting an apostrophe in my search box throws up an error [duplicate]

This question already has answers here:
How can I prevent SQL injection in PHP?
(27 answers)
Closed 7 years ago.
I have a perplexing issue that I can't seem to comprehend...
I have two SQL statements:
The first enters information from a form into the database.
The second takes data from the database entered above, sends an email, and then logs the details of the transaction
The problem is that it appears that a single quote is triggering a MySQL error on the second entry only! The first instance works without issue, but the second instance triggers the mysql_error().
Does the data from a form get handled differently from the data captured in a form?
Query 1 - This works without issue (and without escaping the single quote)
$result = mysql_query("INSERT INTO job_log
(order_id, supplier_id, category_id, service_id, qty_ordered, customer_id, user_id, salesperson_ref, booking_ref, booking_name, address, suburb, postcode, state_id, region_id, email, phone, phone2, mobile, delivery_date, stock_taken, special_instructions, cost_price, cost_price_gst, sell_price, sell_price_gst, ext_sell_price, retail_customer, created, modified, log_status_id)
VALUES
('$order_id', '$supplier_id', '$category_id', '{$value['id']}', '{$value['qty']}', '$customer_id', '$user_id', '$salesperson_ref', '$booking_ref', '$booking_name', '$address', '$suburb', '$postcode', '$state_id', '$region_id', '$email', '$phone', '$phone2', '$mobile', STR_TO_DATE('$delivery_date', '%d/%m/%Y'), '$stock_taken', '$special_instructions', '$cost_price', '$cost_price_gst', '$sell_price', '$sell_price_gst', '$ext_sell_price', '$retail_customer', '".date('Y-m-d H:i:s', time())."', '".date('Y-m-d H:i:s', time())."', '1')");
Query 2 - This fails when entering a name with a single quote (for example, O'Brien)
$query = mysql_query("INSERT INTO message_log
(order_id, timestamp, message_type, email_from, supplier_id, primary_contact, secondary_contact, subject, message_content, status)
VALUES
('$order_id', '".date('Y-m-d H:i:s', time())."', '$email', '$from', '$row->supplier_id', '$row->primary_email' ,'$row->secondary_email', '$subject', '$message_content', '1')");
You should be escaping each of these strings (in both snippets) with mysql_real_escape_string().
http://us3.php.net/mysql-real-escape-string
The reason your two queries are behaving differently is likely because you have magic_quotes_gpc turned on (which you should know is a bad idea). This means that strings gathered from $_GET, $_POST and $_COOKIES are escaped for you (i.e., "O'Brien" -> "O\'Brien").
Once you store the data, and subsequently retrieve it again, the string you get back from the database will not be automatically escaped for you. You'll get back "O'Brien". So, you will need to pass it through mysql_real_escape_string().
For anyone finding this solution in 2015 and moving forward...
The mysql_real_escape_string() function is deprecated as of PHP 5.5.0.
See: php.net
Warning
This extension is deprecated as of PHP 5.5.0, and will be removed in the future. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide and related FAQ for more information. Alternatives to this function include:
mysqli_real_escape_string()
PDO::quote()
You should do something like this to help you debug
$sql = "insert into blah values ('$myVar')";
echo $sql;
You will probably find that the single quote is escaped with a backslash in the working query. This might have been done automatically by PHP via the magic_quotes_gpc setting, or maybe you did it yourself in some other part of the code (addslashes and stripslashes might be functions to look for).
See Magic Quotes
You have a couple of things fighting in your strings.
lack of correct MySQL quoting (mysql_real_escape_string())
potential automatic 'magic quote' -- check your gpc_magic_quotes setting
embedded string variables, which means you have to know how PHP correctly finds variables
It's also possible that the single-quoted value is not present in the parameters to the first query. Your example is a proper name, after all, and only the second query seems to be dealing with names.
You can do the following which escapes both PHP and MySQL.
<?
$text = '';
?>
This will reflect MySQL as
How does it work?
We know that both PHP and MySQL apostrophes can be escaped with backslash and then apostrophe.
\'
Because we are using PHP to insert into MySQL, we need PHP to still write the backslash to MySQL so it too can escape it.
So we use the PHP escape character of backslash-backslash together with backslash-apostrophe to achieve this.
\\\'
You should just pass the variable (or data) inside "mysql_real_escape_string(trim($val))"
where $val is the data which is troubling you.
I had the same problem and I solved it like this:
$text = str_replace("'", "\'", $YourContent);
There is probably a better way to do this, but it worked for me and it should work for you too.
mysql_real_escape_string() or str_replace() function will help you to solve your problem.
http://phptutorial.co.in/php-echo-print/

Why do you need a specific syntax to insert data into postgresql

I have found a way to insert data into a postgresql database using php. Therefore, I used the following syntax:
$sql = "INSERT INTO genes
(id,gene,plasmid,accessionnumber,plasmidname)
VALUES ('".$var_id."','".$var_gene."','".$var_ACC."','".$var_PN."')";
Why do you have to use quotes within quotes and adding a point before and after the variable?
The answer on the question is point concatenates your string, quotes you use to separate literal from variables. (Vao Tsun)

IP address not being saved to database using MySQLi [duplicate]

This question already has answers here:
When to use single quotes, double quotes, and backticks in MySQL
(13 answers)
Closed 6 years ago.
I tried to create a script which will save all the IP address that came to my website (for adwords checking purposes). However when I try, the code doesnt save to database at all. Here is the code:
<?php
session_start();
// Create connection
$mysqli = new mysqli("localhost", "hashmicr_admineq", "monkeycool100", "hashmicr_sessionchecker");
date_default_timezone_set('Asia/Singapore');
$date = date("Y-m-d H:i:s");
$query = "INSERT INTO sessioncheck(ipaddress,date) VALUES (".$_SERVER['SERVER_ADDR'].", ".$date.")";
$mysqli->query($query);
/* close connection */
$mysqli->close();
?>
This is placed on the top of the PHP page.
Did I miss on any steps?
Need to add single quotes as both the field values contain non-numeric (other than 0-9) characters.
You can insert only numeric without single quotes.
Corrected SQL:
$query = "INSERT INTO sessioncheck(ipaddress,date)
VALUES ('".$_SERVER['SERVER_ADDR']."', '".$date."')";

PHP and SQL parsing single quotes [duplicate]

This question already has answers here:
How can I prevent SQL injection in PHP?
(27 answers)
Closed 7 years ago.
I've done some searching here and have not found what I'm looking for.
I've got a form that gets filled out, upon submitting it adds it to an SQL database (using PHP). However, if someone puts an apostrophe or single quote, it will blow up...I need to be able to either parse each text field to check for single quotes to escape them out or find some other way for this to work. Here is my SQL statement...if it helps.
$query = "INSERT INTO workshopinfo (Year, Presentername, email, bio, arrival, title, description, costyn, matcost, schedlimit, additionalinfo, typeofws, verified)" .
"VALUES ('$year', '$presentername', '$email', '$bio', '$arrival', '$title', '$description', '$costyn', '$matcost', '$schedlimit', '$additionalinfo', '$typeofws', '$verified')";
So of course a single quote will blow it up, as will a double quote...it fails every time. There is likely an easy solution to this.
I may have just found it after posting. The php functon addslashes() works in this case.
You can use PDO with prepared statements to handle quotes in SQL requests :
$req = $bdd->prepare("INSERT INTO yourTable (a, b, c) VALUES (:a, :myb, :c)");
$req->bindParam("a", $name, PDO::PARAM_STR); // string
$req->bindParam("myb", $title, PDO::PARAM_STR); // string
$req->bindParam("c", $identifier, PDO::PARAM_INT); // integer
$req->execute();
With this, you avoid all SQL injections.
Documentation : http://php.net/manual/en/book.pdo.php

PHP array INSERT into MySQL failing [duplicate]

This question already has an answer here:
Syntax error due to using a reserved word as a table or column name in MySQL
(1 answer)
Closed 8 years ago.
Many posts similar to mine,none of them work.
Have an array $data['date'], $data['name'], $data['value'].
Trying to insert into MySQL table MyValues (Date, Name, Value)
Have tried 7-8 different methods, none working.
Would like something like
for ($a=0;$a<10;$a++) {
mysql_query("INSERT INTO MyValues('Date','Index_Name','Index')
VALUES ($data['date'][$a] ,$data['name'][$a], $data['value'][$a])"
}
Have also tried foreach, building a single string to give to MySQL, etc.
Get this error
Warning: mysql_error() expects parameter 1 to be resource, boolean given on line 45
columnName shouldn't be wrap with single quotes as they are identifiers not string literals.
INSERT INTO `Values` (Date,Index_Name,Index) VALUES (....)
one more thing, the only identifier here that needs to be wrap with backtick is the tableName VALUES because it is a Reserved Keyword.
MySQL Reserved Keywords List
When to use single quotes, double quotes, and backticks in MySQL
As a sidenote, the query is vulnerable with SQL Injection if the value(s) of the variables came from the outside. Please take a look at the article below to learn how to prevent from it. By using PreparedStatements you can get rid of using single quotes around values.
How to prevent SQL injection in PHP?
Since Values is a reserved word, you can't use it as is for a table name. You must use backticks to enclose it. Similarly, it is not valid to use single quotes to name columns, you need backticks there too.
Try this:
$out = Array();
$esc = "mysql_real_escape_string";
foreach($data['date'] as $k=>$v) {
$out[] = "('".$esc($data['date'][$k])."', '".$esc($data['name'][$k])."', "
."'".$esc($data['value'][$k])."')";
}
mysql_query("INSERT INTO `Values` (`Date`, `Index_Name`, `Index`) values ".implode(",",$out));
try this, use $a++ not $ee++
for ($a=0;$a<10;$a++) {
mysql_query("INSERT INTO `Values` (`Date`,`Index_Name`,`Index`)
VALUES ('".$data['date'][$a]."' ,'".$data['name'][$a]."', '".$data['value'][$a]."' ")
}
First, I believe you want your query values quoted, so the result is 'value' and not just value. Example:
mysql_query("INSERT INTO Values(Date,Index_Name,Index) VALUES ('$data['date'][$a]' ,'$data['name'][$a]', '$data['value'][$a]');
If you are doing multiple queries, do something like:
$q = "INSERT INTO Values(Date,Index_Name,Index) VALUES ";
for {
// Add to the string here for each insert item
}
mysql_query($q);
Additionally, please start phasing out PHP's mysql_* library in favor of mysqli or PDO.
First of all, just use PDO/mysqli with prepared statements so you wont ever have any issues like this.
This will solve it though (column names with back-ticks instead of single quotes, and escaped data):
for ($a=0;$a<10;$a++) {
mysql_query("INSERT INTO `Values` (`Date`,`Index_Name`,`Index`)
VALUES ('".mysql_real_escape_string($data['date'][$a])."' ,
'".mysql_real_escape_string($data['name'][$a])."',
'".mysql_real_escape_string($data['value'])[$a]."'");
}
And try to avoid reserved names for your columns like indexand values.
This works:
for ($a=0;$a<10;$a++) {
mysql_query("INSERT INTO Values('Date','Index_Name','Index')
VALUES ('".$data['date'][$a]."','".$data['name'][$a]."','".$data['value'][$a]."')"
}

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