PDF Report - returning NULL in sub-selection (pls help me)

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#1

Hello to all,

I’m trying to make a subselect in a report pdf but the result is “Null”

Can anyone tell me where did I go wrong?

here is the code:


$curent_id = {id};
//sub_db = ex
function fetch_ex()  
{
 
$output = '';
$con = mysqli_connect("*****************","*****************","*****************","*****************") or die("Some error occurred during connection " . mysqli_error($con)); 
// Write query
 
$strSQL = "SELECT 
   _mr.id,
   _ex.id_mr,
   _ex.pos,
   _ex.com,
   _ex.date_f,
   _ex.date_t,
   _ex.exp
FROM
   _mr INNER  JOIN _ex ON _ex.id_mr = _mr.id
   WHERE _ex.id_mr = '".$curent_id."'";
 
var_dump($strSQL);
// Execute the query.
 
$query = mysqli_query($con, $strSQL);
 
if ($query->num_rows > 0) 
{
while($row = mysqli_fetch_array($query))
{
   $output .= '<tr>
     <td style="width:20%; text-align: left;">'.date("M.Y -", strtotime($row["date_f"])).'<br>'.date("M.Y", strtotime($row["date_t"])).'</td>
</tr>';
}
return $output;
 
}
}
 
var_dump($query);
$exp = fetch_exp();
 
//Close the connection
mysqli_close($con);

This select returns at var_dump($query);

NULL string(312) “SELECT _mr.id, _ex.id_mr, _ex.pos, _ex.com, _ex.date_f, _ex.date_t, _ex.exp FROM _mr INNER JOIN _ex ON _ex.id_mr = _mr.id WHERE _ex.id_mr = ‘’”

Observations:

  1. If I use instead of this parameter $curent_id a number (from the id list) everything works great;
  2. if I make this parameter $curent_id = with a number I have the same error >> NULL string(312) “SELECT _mr.id, _ex.id_mr, _ex.pos, _ex.com, _ex.date_f, _ex.date_t, _ex.exp FROM _mr INNER JOIN _ex ON _ex.id_mr = _mr.id WHERE _ex.id_mr = ‘’” <<

Does have anyone any ideas?

Thank you for your help,
Dan

#2

Hello all,

so I figured my self.

the problem was that I wanted to use an external variable inside of my function “fetch”

The correct variant of the code is the following:

$curent_id = {id};
//sub_db = ex
function fetch_ex($x_var)
{

$output = ‘’;
$con = mysqli_connect(“","”,“","”) or die("Some error occurred during connection " . mysqli_error($con));
// Write query

$strSQL = "SELECT
_mr.id,
_ex.id_mr,
_ex.pos,
_ex.com,
_ex.date_f,
_ex.date_t,
_ex.exp
FROM
_mr INNER JOIN _ex ON _ex.id_mr = _mr.id
WHERE _ex.id_mr = ".$x_var;

var_dump($strSQL);
// Execute the query.

$query = mysqli_query($con, $strSQL);

if ($query->num_rows > 0)
{
while($row = mysqli_fetch_array($query))
{
$output .= ‘<tr>
<td style=“width:20%; text-align: left;”>’.date(“M.Y -”, strtotime($row[“date_f”])).’<br>’.date(“M.Y”, strtotime($row[“date_t”])).’</td>
</tr>’;
}
return $output;

}
}

var_dump($query);
$exp = fetch_exp($current_id);

//Close the connection
mysqli_close($con);

What’s in red was changed in order to make the function to work.

Hope this will help someone.

Regards,
Dan