PHP check if value exists - php

Question

I’m trying to write a if code, but can't figure out how.
In my database table i have the primary key id.
In the table i have objekt_nr & element_nr.
Now, before i call an INSTERT i need to check if objekt_nr with element_nr already exist.
If objekt_nr With element_nr exist. Then UPDATE instead of INSTERT. Only id can be unique.
example of table:
id......objekt_nr......element_nr
1.......1...............1
2.......1...............2
3.......1...............3
4.......2...............1
5.......2...............2
PHP:
if(isset($_POST["Import"])){
echo 'Fortsätt...<br />';
echo $path=$_FILES["file"]["tmp_name"];
//Load file into PHPExcel
$objPHPExcel = PHPExcel_IOFactory::load($path);
//Loop threw file to get data
foreach ($objPHPExcel->getWorksheetIterator() as $worksheet) {
$worksheetTitle = $worksheet->getTitle();
$highestRow = $worksheet->getHighestRow(); // e.g. 10
$highestColumn = 'J'; //$worksheet->getHighestColumn(''); // e.g 'F'
$highestColumnIndex = PHPExcel_Cell::columnIndexFromString($highestColumn);
$nrColumns = ord($highestColumn) - 64;
//Echo file info
echo "<br>The worksheet ".$worksheetTitle." has ";
echo $nrColumns . ' columns (A-' . $highestColumn . ') ';
echo ' and ' . $highestRow . ' row.';
echo '<br>Data: <table border="1"><tr>';
//Loop threw colum, rows and cells
for ($row = 2; $row <= $highestRow; ++ $row) {
echo '<tr>';
for ($col = 0; $col < $highestColumnIndex; ++ $col) {
$cell = $worksheet->getCellByColumnAndRow($col, $row);
$val = $cell->getCalculatedValue();
//$dataType = PHPExcel_Cell_DataType::dataTypeForValue($val);
echo '<td>' . $val . '<br></td>';
}
echo '</tr>';
}
echo '</table>';
}
for ($row = 2; $row <= $highestRow; ++ $row) {
$val=array();
for ($col = 0; $col < $highestColumnIndex; ++ $col) {
$cell = $worksheet->getCellByColumnAndRow($col, $row);
$val[] = $cell->getCalculatedValue();
}
// Prepare Query
$query = "INSERT INTO phpexcel(
objekt_nr,
objekt_rev,
element_nr,
element_hojd,
element_typ,
element_langd,
element_oppningar,
element_vikt,
element_ritare,
element_status)
VALUES (
:objekt_nr,
:objekt_rev,
:element_nr,
:element_hojd,
:element_typ,
:element_langd,
:element_oppningar,
:element_vikt,
:element_ritare,
:element_status
)";
// Security measures
$query_params = array(
':objekt_nr' => $val[0],
':objekt_rev' => $val[1],
':element_nr' => $val[2],
':element_hojd' => $val[3],
':element_typ' => $val[4],
':element_langd' => $val[5],
':element_oppningar' => $val[6],
':element_vikt' => $val[7],
':element_ritare' => $val[8],
':element_status' => $val[9]
);
try {
$stmt = $db->prepare($query);
$result = $stmt->execute($query_params);
}
catch(PDOException $ex){ die("Failed to run query: " . $ex->getMessage()); }
//echo $query."\n";
}
}

Answer 1

Two options here.
1) Make "objekt_nr" field a PRIMARY or UNIQUE key and use REPLACE instead of INSERT (http://dev.mysql.com/doc/refman/5.0/en/replace.html). This is pretty much #hd 's answer in the comments.
2) Check for an existing "objekt_nr" and "element_nr" and run the appropriate query
$check_duplicate_query = "SELECT COUNT(*) FROM phpexcel WHERE objekt_nr = ':objekt_nr' AND element_nr = ':element_nr'";
$stmt = $db->prepare($check_duplicate_query);
$result = $stmt->execute($query_params);
$rows = $stmt->fetch(PDO::FETCH_NUM);
if($rows[0] > 0) {
//UPDATE
} else {
//INSERT
}
$stmt = $db->prepare($query);
$result = $stmt->execute($query_params);
EDIT:
Just thought of a 3rd option
Create another field "objekt_element_nr" and set this field to unique.
This field gets assigned objekt and element number combination, which from your example should be unique.
e.g. 1_1, 1_2, 1_3, 2_1, 2_2, etc.
Then simply use the REPLACE function I linked to above.
Your $query_params would look like
$query_params = array(
':objekt_nr' => $val[0],
':objekt_rev' => $val[1],
':element_nr' => $val[2],
':objekt_element_nr' => $val[0].'_'.$val[2]
':element_hojd' => $val[3],
':element_typ' => $val[4],
':element_langd' => $val[5],
':element_oppningar' => $val[6],
':element_vikt' => $val[7],
':element_ritare' => $val[8],
':element_status' => $val[9]
);