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May 30th, 2008

PHP Variable in MySQL Statement

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When I use the following PHP code I get this error

Error performing query: Unknown column 'nh12134' in 'where clause'

Yet when I use 'nh12345', which is the Value that the variable $username contains (i've checked that it does by printing it out elsewhere) instead of the $username in the query it returns the correct value.

php Syntax (Toggle Plain Text)
$tutorname = @mysql_query("SELECT Personal_tutor FROM Student WHERE student_ref=$username;"); 
if (!$tutorname) {
exit ('<p> Error performaing query: ' . mysql_error() . '</p>');
}
$tutorname = @mysql_query("SELECT Personal_tutor FROM Student WHERE student_ref=$username;"); 
if (!$tutorname) {
exit ('<p> Error performaing query: ' . mysql_error() . '</p>');
}

Any help is much appreciated

Thanks
NH

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twelvetwelve

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since Jan 2007

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May 30th, 2008

Re: PHP Variable in MySQL Statement

someting like this:

PHP Syntax (Toggle Plain Text)
$query = sprintf("SELECT Personal_tutor FROM Student WHERE student_ref='%s' ",
    mysql_real_escape_string( $username));
 
$tutorname = @mysql_query($query); 
if (!$tutorname) {
exit ('<p> Error performaing query: ' . mysql_error() . '</p>');
}
$query = sprintf("SELECT Personal_tutor FROM Student WHERE student_ref='%s' ",
    mysql_real_escape_string( $username));

$tutorname = @mysql_query($query); 
if (!$tutorname) {
exit ('<p> Error performaing query: ' . mysql_error() . '</p>');
}

pzuurveen

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May 30th, 2008

Re: PHP Variable in MySQL Statement

try this

php Syntax (Toggle Plain Text)
$tutorname = mysql_query("SELECT Personal_tutor FROM Student WHERE student_ref = '".$username."'");
$tutorname = mysql_query("SELECT Personal_tutor FROM Student WHERE student_ref = '".$username."'");

Last edited by ProfessorPC; May 30th, 2008 at 8:50 am.

ProfessorPC

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May 30th, 2008

Re: PHP Variable in MySQL Statement

PHP Syntax (Toggle Plain Text)
 
$Search=$_POST['Search'];
 
$query_Retrieve = "Select Model,Prime_kVA,Prime_kW,Engine, Alternator,Cylinders,Bore, Stroke,Governer,Type, Retail WHERE (`$Search` like '%{$_POST[Engine]}%') OR (`$Search` like '%{$_POST[Type]}%')";
 
$Search=$_POST['Search'];

$query_Retrieve = "Select Model,Prime_kVA,Prime_kW,Engine, Alternator,Cylinders,Bore, Stroke,Governer,Type, Retail WHERE (`$Search` like '%{$_POST[Engine]}%') OR (`$Search` like '%{$_POST[Type]}%')";

The above code produces: Wrong results

I have checked that the values are passed correctly.

The idea is that on the refering page the client selects the field to use when doing the query. I have never used variable to indicate the table in the query. Can someone please help me with this.

Last edited by Peterpan71; May 30th, 2008 at 4:03 pm.

Peterpan71

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May 30th, 2008

Re: PHP Variable in MySQL Statement

so you want to display everything from this table depending on the users search criteria. you are allowing the user to specify what field to search through. so you will need to grab 2 var's from other page.

php Syntax (Toggle Plain Text)
$col = $_POST['column'];
$search = $_POST['search'];
$query = mysql_query("Select Model,Prime_kVA,Prime_kW,Engine, Alternator,Cylinders,Bore, Stroke,Governer,Type, Retail WHERE ".$col." like '%".$search."%'") or die(mysql_error());
while($row = mysql_fetch_assoc($query)){
echo $row['Model']."<br>";
echo $row['Prime_kVA']."<br>";
//continue to display remainder of fields
}
$col = $_POST['column'];
$search = $_POST['search'];
$query = mysql_query("Select Model,Prime_kVA,Prime_kW,Engine, Alternator,Cylinders,Bore, Stroke,Governer,Type, Retail WHERE ".$col." like '%".$search."%'") or die(mysql_error());
while($row = mysql_fetch_assoc($query)){
echo $row['Model']."<br>";
echo $row['Prime_kVA']."<br>";
//continue to display remainder of fields
}

this is assuming you have the column in the other page for the user to select. and the textfield for the user to place the search text.

Last edited by ProfessorPC; May 30th, 2008 at 4:04 pm.

ProfessorPC

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May 30th, 2008

Re: PHP Variable in MySQL Statement

sorry i changed the code lets try that again.

php Syntax (Toggle Plain Text)
$Search=$_POST['Search'];
 
$query_Retrieve = "Select Model,Prime_kVA,Prime_kW,Engine, Alternator,Cylinders,Bore, Stroke,Governer,Type, Retail WHERE (`".$Search."` like '%".$_POST[Engine]."%') OR (`".$Search."` like '%".$_POST[Type]."%')";
$Search=$_POST['Search'];

$query_Retrieve = "Select Model,Prime_kVA,Prime_kW,Engine, Alternator,Cylinders,Bore, Stroke,Governer,Type, Retail WHERE (`".$Search."` like '%".$_POST[Engine]."%') OR (`".$Search."` like '%".$_POST[Type]."%')";

ProfessorPC

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May 30th, 2008

Re: PHP Variable in MySQL Statement

php Syntax (Toggle Plain Text)
 $query_Retrieve = "SELECT Model, Prime_kVA, Prime_kW, Engine, Alternator, Cylinders, Bore, Stroke, Governer, Type,Retail 
 
 
  FROM Import WHERE 
  ((`".$Search."` = '%".$_POST[Engine]."%') AND (`Prime_kVA` = '%".$_POST[Prime_kVA]."%'))
                  OR 
  (`".$Search."` = '%".$_POST[Prime_kVA]."%')
 
  ";
  //OR (`Engine`like '%{$_POST[Engine]}%') OR (`Alternator`like '%{$_POST[Alternator]}%') OR 
  mysql_select_db($database_generators, $generators);
  $Table = mysql_query($query_Retrieve, $generators) or die(mysql_error());
 $query_Retrieve = "SELECT Model, Prime_kVA, Prime_kW, Engine, Alternator, Cylinders, Bore, Stroke, Governer, Type,Retail 
   
  
  FROM Import WHERE 
  ((`".$Search."` = '%".$_POST[Engine]."%') AND (`Prime_kVA` = '%".$_POST[Prime_kVA]."%'))
                  OR 
  (`".$Search."` = '%".$_POST[Prime_kVA]."%')
                   
  ";
  //OR (`Engine`like '%{$_POST[Engine]}%') OR (`Alternator`like '%{$_POST[Alternator]}%') OR 
  mysql_select_db($database_generators, $generators);
  $Table = mysql_query($query_Retrieve, $generators) or die(mysql_error());

When I use "like" instead of the "=" I get results, but if I make the Prime_kVA (10) the the results that comes back is 10, 100 etc. when using the "=" I get no results.

Peterpan71

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Jul 2nd, 2010

Re: PHP Variable in MySQL Statement

Hi
I am very new to PHP an MYSQL
I have almost the same problem,
how can I

$q=$_GET["q"];
$CMY=$get["CMY"];
...

$query=("INSERT INTO the_array($CMY, model)
VALUES('$q','dddd')");

kukie

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Jul 5th, 2010

Re: PHP Variable in MySQL Statement

PHP Syntax (Toggle Plain Text)
$tutorname = @mysql_query("SELECT Personal_tutor FROM Student WHERE student_ref='$username'"); 
if (!$tutorname)
$tutorname = @mysql_query("SELECT Personal_tutor FROM Student WHERE student_ref='$username'"); 
if (!$tutorname)

rajarajan07

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Nearly a Posting Virtuoso

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Jul 5th, 2010

Re: PHP Variable in MySQL Statement

Use Single Quotes for PHP Variables in mysql.

i.e. '$username'

Ankit_Parmar

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