How to pass an array of conditions to a select query class? - php

Question

I am trying to build a class to select records from table defined on user input.
my plan is to make a class that read user input conditions as an array, because there is a lot of other forms for other tables with different number of conditions. therefore I want to make one class that works with all.
basically am trying to achieve this statement:
select * from table_name where condition1=value1 AND condition2=value2
where the number of conditions varies depends on user input.
what I have done is this class:
class SelectQuery {
private $Error;
public $conn;
public $table;
public function __construct($conn){ //establish connection
$this->conn = $conn;
}
public function SelectData($table,$cols,array $conds){
$this->table = $table;
if($cols)
{
if($conds)
{
$i=0; $cond='';
foreach ($conds as $key => $value){
if($i==0)
{
$cond .= $key. '=' .$value;
}
else
{
$cond .= ' AND ' .$key. '=' .$value;
}
$i++;
}
$sql = 'SELECT '.$cols.' FROM '.$table.' WHERE '.$cond.'';
$stmt = oci_parse($this->conn, $sql);
oci_execute($stmt);
$rows = oci_fetch_all($stmt, $data, null, null, OCI_FETCHSTATEMENT_BY_COLUMN);
if($rows)
{
return $rows['0']['0'];
}
else
{
return NULL;
}
}
else
{
$sql = 'SELECT {$cols} FROM {$table}';
$stmt = oci_parse($this->conn, $sql);
oci_execute($stmt);
$rows = oci_fetch_all($stmt, $data, null, null, OCI_FETCHSTATEMENT_BY_COLUMN);
if($rows)
{
return $rows['0']['0'];
}
else
{
return NULL;
}
}
}
}
and this is how the data is sent from form:
$manager = new OracleConnectManager();
$conn = $manager->establishConnection(); //establish connection
if( $conn ){
$table = 'MAIN';
$cols= '*';
$conds = array(
'id_number' => $_POST['id_number'],
'firstname' => $_POST['firstname'],
'secondname' => $_POST['secondname'],
'thirdname' => $_POST['thirdname'],
'familyname' => $_POST['familyname'],
'department' => $_POST['department'],
);
$sel = new SelectQuery($conn);
$dth = $sel->SelectData($table,$cols,$conds);
echo $dth;
}
when I run the code i get this error:
Warning: oci_execute(): ORA-00936: missing expression
(in the SelectQuery class, line: oci_execute($stmt); )
Warning: oci_fetch_all(): ORA-24374: define not done before fetch or execute and fetch
(in the SelectQuery class, line: $rows = oci_fetch_all($stmt, $data, null, null, OCI_FETCHSTATEMENT_BY_COLUMN); )
and there is no output.
any help would be appreciated.
thanks

Answer 1

There are two things:
You need to validate all the $_POST values and build $conds array for values that are set in $_POST.
Update:
i.e. if you have only one or two post values then the $conds array should be:
$conds = array(
'id_number' => $_POST['id_number'],
'firstname' => $_POST['firstname']
)
In your foreach loop, $value needs to be quoted if it is varchar type as:
foreach ($conds as $key => $value){
if($i==0)
{
$cond .= "$key='$value'";
}
else
{
$cond .= " AND $key='$value'";
}
$i++;
}
Update:
if you have int and varchar fields then do formatting when building array itself:
$conds = array(
'id_number' => $_POST['id_number'], // int type
'firstname' => "'".$_POST['firstname']."'" // string type
)

Answer 2

else
{
$sql = 'SELECT ' . $cols . ' FROM ' . $table;
// Other Statements
}
Hope the ELSE part for $sql should be framed like above?