How to Concatenate table name with with a variable value in mySQL - php

I'm trying to create a dynamic code that would ready from any table with the certain name but the difference between each table name is a number that is generated by a variable: for example :
//that's how I get my variable the value for example is = 3
$pid = $GLOBALS["localid"];
//the table name for example is tablename_3
$strTable = "tablename_" .$pid;
//here's how the query should look like
$query = "SELECT * FROM . $strTable . where .....;
I'm making a mistake somewhere but can't figure it out and would appreciate a little help please

Remove the dots and also make sure you have single quotes aroung where
$query = "SELECT * FROM $strTable where '.....';

Besides the comments about do or don't build your queries like this...
You're not closing the quotes properly.
$query = "SELECT * FROM . $strTable . where .....; //Double quote not closed.
should be:
$query = 'SELECT * FROM' . $strTable . 'where .....'; //Single quoted strings concatenated with variable.
or
$query = "SELECT * FROM $strTable where ....."; //Variable inside double quoted string.

Related

How to add PHP variable in SELECT Query?

I have a problem in add value in SELECT query.
$sql=("SELECT `image` FROM `testtable`");
The output: 123.jpg
But I want output: 127.0.0.1/home/galery/123.jpg
So I tried:
$path='127.0.0.1/home/galery/';
.........
$sql=("SELECT $path+`image` FROM `testtable`");
But it's not working.
There are two ways to accomplish this.
Method 1:
Use string concatenation to join the path to the result from the SQL:
$path = '127.0.0.1/home/galery/';
$sql = "SELECT `image` FROM `testtable`";
// Run the query...
$result = $path . $sql;
In php, string concatenation is performed with the . operator. Also see here.
Method 2:
The second method is via the CONCAT SQL function:
$sql = "SELECT CONCAT('" . $path . "', `image`) FROM `testtable`";
Or:
$sql = "SELECT CONCAT('{$path}', `image`) FROM `testtable`";
See this question for the difference between these options.
$sql=("SELECT CONCAT('$path',`image`) FROM `testtable`");
Use concatenation like below....
$sql=("SELECT".$path."+image FROM test")
Here, text in double quotes are string

PHP string variable in WHERE clause MySQL

I am having a problem with this simple sql query:
<?php
require_once('../../Connections/tohoshows.php');
$show ='gothaf';
mysql_select_db($database_tohoshows, $tohoshows);
$query_getShows = "SELECT * FROM toho_shows WHERE toho_shows.show =' ". $show. " '";
$getShows = mysql_query($query_getShows, $tohoshows) or die(mysql_error());
$row_getShows = mysql_fetch_assoc($getShows);
$totalRows_getShows = mysql_num_rows($getShows);
mysql_free_result($getShows);
?>
When I use the string directly in the WHERE clause like this
$query_getShows = "SELECT * FROM toho_shows WHERE toho_shows.show ='gothaf'";
I get a result. When I use the variable instead, I get no data! I am a novice and I can't figure out what am I doing wrong. Any help would be appreciated.
Thank you!
you getting no date because you have extra space betwee the quotes,
$query_getShows = "SELECT * FROM toho_shows WHERE toho_shows.show =' ". $show. " '";
^ HERE ^
which will then be parsed into
SELECT * FROM toho_shows WHERE toho_shows.show =' gothaf '
remove it and it will work
$query_getShows = "SELECT * FROM toho_shows WHERE toho_shows.show ='". $show. "'";
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?

php with SQL query

i have a problem with php in the following:
$sql = 'SELECT name FROM chiled WHERE `im` LIKE $id ';
$query = mysql_query( $sql );
$a=mysql_fetch_row($query);
echo $a[0];
there is error in mysql_fetch_row($query);
but if i do the following :
$sql = 'SELECT name FROM chiled WHERE `im` LIKE 1111 ';
$query = mysql_query( $sql );
$a=mysql_fetch_row($query);
echo $a[0];
it is working and prints the name
can you please tell me what is wrong?
Single quotes in PHP doesn't evaluate embedded variables - you need to use double quotes to do that. (See the "Single quoted" section of the PHP Strings manual page for more info..)
i.e.: $sql = "SELECT name FROM chiled WHERE 'im' LIKE $id ";
Or better still...
$sql = 'SELECT name FROM chiled WHERE im="' . mysql_real_escape_string($id) . '"';
(As you're not using the % in your like, you're presumably not attempting to do any form of pattern matching.)
Additionally, I'd recommend a read of the existing Best way to stop SQL Injection in PHP question/answers.
Are you sure you want to be using LIKE? It looks more to me like you want to see if im = $id. Also, make sure you're escaping your variables before using them in the query.
Edit
If you DO want to us LIKE, you probably want something like this:
$sql = "SELECT name FROM chiled WHERE `im` LIKE '%$id%' ";
which will find anywhere that the string $id is found in the im column.
You need to quote the variable after LIKE, like this:
$sql = "SELECT name FROM chiled WHERE im LIKE '$id'";
$query = mysql_query($sql);
$a = mysql_fetch_row($query);
echo $a[0];
// ....
Beside, you are using single quotes, Therefore, $id is not replaced for its value. Your query look like this:
SELECT name FROM chiled WHERE im LIKE $id;
$sql = "SELECT name FROM chiled WHERE `im` LIKE '$id' ";
change to double quotes - http://php.net/manual/en/language.types.string.php

MYSQL WHERE clause is wrong value

Whenever I try to perform my query, It gives me an unknown column error, because it is using my variable as the column name.
essentially
$search="lname";
$term="asdas";
(both of those are variables from a form on another page)
I run this:
if (isset($term))
{
$query = "SELECT * FROM test
WHERE $search = $term ";
}
else
{
$query = "SELECT * FROM test";
}
echo $query;
$result=mysql_query($query) or die(mysql_error());
and then I get this as my error:
Unknown column 'asdas' in 'where clause'
You need to enclose the search term in single quotes(also use mysql_real_escape_string to avoid any issues with quotes in the search string.).
i.e:
if (isset($term))
{
$query = "SELECT * FROM test WHERE $search = '" . mysql_real_escape_string($term) . "' ";
}
You need to quote it.
if (isset($term))
{
$query = "SELECT * FROM test
WHERE $search = '$term' ";
}
else
{
$query = "SELECT * FROM test";
}
echo $query;
$result=mysql_query($query) or die(mysql_error());
Other comments
It is always better to use parameterized queries if the driver supports it. It will prevent SQL injection. As it stands, someone could send in a string "' or ''='" and the query turns out to be
SELECT * FROM test WHERE col1 = '' or ''=''
which is really benign but unexpected behaviour. If the string contains single quotes, it also breaks your query (input is "o'neil")
SELECT * FROM test WHERE col1 = 'o'neil' # << unmatched quotes
So, at the very least use mysql_real_escape_string if you cannot use parameters, i.e.
$query = "SELECT * FROM test
WHERE $search = '" . mysql_real_escape_string($term) . "' ";
You need to quote your $term parameter:
// protect from trivial sql injection attacks.
$term = mysql_real_escape_string("adas");
$query = "SELECT * FROM test
WHERE $search = '$term'";
You have to surround the term value with quotes:
SELECT *
FROM test
WHERE lname='asdas'
otherwise any SQL server out there will think asdas is a field name and try to find it in the table.
Add ' around your columns
$query = "SELECT * FROM test WHERE $search = '$term' ";
you need to put single quotes around $term so that the SQL thinks it's a string
put single quote string always be quoted. Do not forgot use mysql_real_escape_sring()
$query = "SELECT * FROM test
WHERE $search = '$term' ";
Put single quotes around $term
if (isset($term))
{
$query = "SELECT * FROM test WHERE $search = '$term'";
}
else
{
$query = "SELECT * FROM test";
}
echo $query;
$result=mysql_query($query) or die(mysql_error());

Small Php and MySql problem

I have an array of ID:s, and the ID:s are in this format:
Bmw_330ci_89492822
So it's a string!
Now, I have this code to find whatever is in that array, in MySQL:
($solr_id_arr is the array I mentioned above, it contains string ID:s)
ex: $solr_id_arr[0] outputs Bmw_330ci_89492822
$solr_id_arr_imploded = implode(", ", $solr_id_arr);
$query = "SELECT * FROM my_table WHERE ad_id IN ('$solr_id_arr_imploded')";
$qry_result = mysql_query($query) or die(mysql_error());
Problem is this wont work because (I think) that there should be quotes around each of the imploded elements in order for MySQL to find the match. The field in MySQL I am matching is of type Varchar.
Here is the $query echoed:
SELECT * FROM my_table WHERE ad_id IN ('Bmw_m3_cool_565440282, Bmw_m5_839493889')
Do you have any other solutions for this, all I need is to find matches in MySQL which are inside this array!
Thanks
Don't surround the entire thing in quotes. It is looking for where ad_id is 'Bmw_m3_cool_565440282, test'
Use
SELECT * FROM my_table WHERE ad_id IN ('Bmw_m3_cool_565440282', 'test')
A quick fix would be to change:
//this
$solr_id_arr_imploded = implode(", ", $solr_id_arr);
//to this
$solr_id_arr_imploded = implode("', '", $solr_id_arr);
This one seems complicated but it's more safer and fastest one
function escaped($str)
{
return mysql_escape_string($str);
}
$arrayOfIds = array_map("escaped", $solr_id_arr);
$solr_id_arr_imploded = implode(", ", $arrayOfIds);
$query = "SELECT * FROM my_table WHERE ad_id IN ('$solr_id_arr_imploded')";
$qry_result = mysql_query($query) or die(mysql_error());
Simple switch to ', ' in implode():
implode("', '", $solr_id_arr);
This, together with the hardcoded quotes in the SQL string will format them as separate items.
Previous answers will work fine.
Just make sure the strings themselves do not contain quotes. If they do, escape each string before you do the implode().
If it were my code I'd write it like this:
$solr_id_arr_imploded = "'" . implode("', '", $solr_id_arr) . "'";
$query = "SELECT * FROM my_table WHERE ad_id IN ($solr_id_arr_imploded)";
$qry_result = mysql_query($query) or die(mysql_error());
...just because it keeps all the quoting work in one place. You might also want to make sure that the array isn't empty before entering this block of code. Otherwise the SELECT will match all empty ad_id's, which probably isn't what you wanted. We're also assuming that the elements of the array don't include any quote characters (or user-provided strings that haven't been sanity-checked).

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