Tuesday, 6 November 2018

PHP code to convert a MySQL query to CSV

What is the most efficient way to convert a MySQL query to CSV in PHP please?
It would be best to avoid temp files as this reduces portability (dir paths and setting file-system permissions required).
The CSV should also include one top line of field names.

 Answers


SELECT * INTO OUTFILE "c:/mydata.csv"
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
LINES TERMINATED BY "\n"
FROM my_table;
(the documentation for this is here: http://dev.mysql.com/doc/refman/5.0/en/select.html)
or:
$select = "SELECT * FROM table_name";

$export = mysql_query ( $select ) or die ( "Sql error : " . mysql_error( ) );

$fields = mysql_num_fields ( $export );

for ( $i = 0; $i < $fields; $i++ )
{
    $header .= mysql_field_name( $export , $i ) . "\t";
}

while( $row = mysql_fetch_row( $export ) )
{
    $line = '';
    foreach( $row as $value )
    {                                            
        if ( ( !isset( $value ) ) || ( $value == "" ) )
        {
            $value = "\t";
        }
        else
        {
            $value = str_replace( '"' , '""' , $value );
            $value = '"' . $value . '"' . "\t";
        }
        $line .= $value;
    }
    $data .= trim( $line ) . "\n";
}
$data = str_replace( "\r" , "" , $data );

if ( $data == "" )
{
    $data = "\n(0) Records Found!\n";                        
}

header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=your_desired_name.xls");
header("Pragma: no-cache");
header("Expires: 0");
print "$header\n$data";



Look at the documentation regarding the SELECT ... INTO OUTFILE syntax.
SELECT a,b,a+b INTO OUTFILE '/tmp/result.txt'
  FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
  LINES TERMINATED BY '\n'
  FROM test_table;



If you'd like the download to be offered as a download that can be opened directly in Excel, this may work for you: (copied from an old unreleased project of mine)
These functions setup the headers:
function setExcelContentType() {
    if(headers_sent())
        return false;

    header('Content-type: application/vnd.ms-excel');
    return true;
}

function setDownloadAsHeader($filename) {
    if(headers_sent())
        return false;

    header('Content-disposition: attachment; filename=' . $filename);
    return true;
}
This one sends a CSV to a stream using a mysql result
function csvFromResult($stream, $result, $showColumnHeaders = true) {
    if($showColumnHeaders) {
        $columnHeaders = array();
        $nfields = mysql_num_fields($result);
        for($i = 0; $i < $nfields; $i++) {
            $field = mysql_fetch_field($result, $i);
            $columnHeaders[] = $field->name;
        }
        fputcsv($stream, $columnHeaders);
    }

    $nrows = 0;
    while($row = mysql_fetch_row($result)) {
        fputcsv($stream, $row);
        $nrows++;
    }

    return $nrows;
}
This one uses the above function to write a CSV to a file, given by $filename
function csvFileFromResult($filename, $result, $showColumnHeaders = true) {
    $fp = fopen($filename, 'w');
    $rc = csvFromResult($fp, $result, $showColumnHeaders);
    fclose($fp);
    return $rc;
}
And this is where the magic happens ;)
function csvToExcelDownloadFromResult($result, $showColumnHeaders = true, $asFilename = 'data.csv') {
    setExcelContentType();
    setDownloadAsHeader($asFilename);
    return csvFileFromResult('php://output', $result, $showColumnHeaders);
}
For example:
$result = mysql_query("SELECT foo, bar, shazbot FROM baz WHERE boo = 'foo'");
csvToExcelDownloadFromResult($result);

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