how to query a csv value in php? - php

Question

I'm currently using this script:
<?php function jj_readcsv($filename, $header=false) { $handle = fopen($filename, "r"); echo '<table>'; //display header row if true if ($header) {
$csvcontents = fgetcsv($handle);
echo '<tr>';
foreach ($csvcontents as $headercolumn) {
echo "<th>$headercolumn</th>";
}
echo '</tr>'; } // displaying contents while ($csvcontents = fgetcsv($handle)) {
echo '<tr>';
foreach ($csvcontents as $column) {
echo "<td>$column</td>";
}
echo '</tr>'; } echo '</table>'; fclose($handle); } jj_readcsv('partitiontable.csv',true);
?>
I have a CSV table with 8 columns.
I would like to know if it possible to get only on element of the column when making a query. Here is what look like my CSV :
"HEMSI, Alberto",P_000001,P_1,Partition,169864,"Hemsi, Myriam","HEMSI, Alberto","Una matica de ruda",
"HEMSI, Alberto",P_000002,P_2,Partition,169865,"Hemsi, Myriam","HEMSI, Alberto","Ya salio de la mar",
the idea is :
query a value for example: P_1
and get in result: Una matica de ruda
For each line, when asking P_1 getting the value which is in the 8 column.
And the same for P_2

Answer 1

Yes, this is possible using two methods:
At the beginning create an associative array and insert as key the 4th column, and as value with 8th column. Then use this as a lookup table in all further code.
If you don't do 1. , you can make a for loop that goes through the CSV data and looks with IF that the 4th row value is the one you are looking for. When found, return the 8th column value.
Example of first approach with associative array
<?php
$array = array();
jj_readcsv("csv.txt");
echo $array["P_1"]."<br/>";
echo $array["P_2"]."<br/>";
function jj_readcsv($filename, $header = false)
{
global $array;
$row = 1;
if (($handle = fopen($filename, "r")) !== FALSE) {
echo '<table>'; //display header row if true if ($header) {
while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
//print_r($data);
$num = count($data);
echo '<tr>';
for ($c=0; $c < $num; $c++) {
if($row > 1)
echo "<td>$data[$c]</td>";
else
echo "<th>$data[$c]</th>";
if($c==2)
$array[$data[$c]]= $data[7];
}
echo '</tr>';
$row++;
}
fclose($handle);
}
}
?>

Answer 2

Try this:
$row = 1;
$handle = fopen ("teste.csv","r");
$head = Array();
while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
//register head rows with names
if($row == 1){
$num = count ($data);
for ($c=0; $c < $num; $c++) {
$colName = trim($data[$c]);
$head[$colName] = $c;
}
}else{
echo $data[$head['COL_NAME']];
}
$row++;
}
fclose ($handle);
This will make var $head an associative array where the key is the col name and value his position in csv, after that you can easy identify what col you want.

Answer 3

Even if you named your function jj_readcsv(), if you look more closely, this name is a liar, the function does much more: opening a file, reading the lines.
If you don't want to separate the concerns but also easily modify it, just make the actual reading method optional:
function jj_readcsv($filename, $header = FALSE, callable $fgetcsv = NULL)
########################
{
$fgetcsv || $fgetcsv = 'fgetcsv';
#################################
$fileHandle = fopen($filename, "r");
if (!$fileHandle) {
return;
}
$csvLine = $fgetcsv($fileHandle);
#####################
echo '<table>';
echo '<tr>';
foreach ($csvLine as $headercolumn) {
echo "<th>$headercolumn</th>";
}
echo '</tr>';
while ($csvLine = $fgetcsv($fileHandle)) {
#####################
echo '<tr>';
foreach ($csvLine as $column) {
echo "<td>$column</td>";
}
echo '</tr>';
}
echo '</table>';
fclose($fileHandle);
}
This little modification allows you to specify the reading function, therefore you can control what is read. So you can inject it as third parameter, for example to only return the eighth column:
jj_readcsv('test.csv', FALSE, function($fileHandle) {
if ($csvLine = fgetcsv($fileHandle))
{
$csvLine = [$csvLine[7]];
}
return $csvLine;
});
Output:
<table><tr><th>Una matica de ruda</th></tr><tr><td>Ya salio de la mar</td></tr></table>