导出PHP CSV文件列未显示

Question

The code below exports data from mysql table correctly but the column names are not displayd in the outputted csv file. Please help

if(isset($_POST["export"])){
    $branchcode=$_POST['branchcode'];
    $start=$_POST['start'];
    $end=$_POST['end'];
    $sql=mysqli_query($conn,"select tk_file,tk_date,userid,tk_from,tk_to from rfc_timekeeping_history where branchcode='$branchcode' and (tk_date between '$start' and '$end');")or die(mysqli_error());
    $output = "";
    $columns_total =    mysqli_num_fields($sql);
    for ($i = 0; $i < $columns_total; $i++) {
    $heading =  mysqli_fetch_fields($sql, $i);
    $output .= '"'.$heading.'",';
    }
    $output .="\n";
    while ($row = mysqli_fetch_array($sql)) {
    for ($i = 0; $i < $columns_total; $i++) {
    $output .='"'.$row["$i"].'",';
    }
    $output .="\n";
    }
    $filename = "myFile.csv";
    header('Content-type: application/csv');
    header('Content-Disposition: attachment; filename='.$filename);
    echo $output;
    exit;
}

Answer 1

A different approach using the standard php methods of writing to a csv file ( fputcsv ) and using stdout stream you could try along these lines. The column names are obtained in the first loop before rewinding the recordset to actually process the recordset data.

<?php

    if( isset( $_POST["export"], $_POST['branchcode'], $_POST['start'], $_POST['end'] ) ){

        $filename = "myFile.csv";
        $branchcode=$_POST['branchcode'];
        $start=$_POST['start'];
        $end=$_POST['end'];



        /* store columns names in this array */
        $headers=array();

        /* Run the query */
        $sql = mysqli_query( $conn, "select `tk_file`,`tk_date`,`userid`,`tk_from`,`tk_to` from `rfc_timekeeping_history` where `branchcode`='{$branchcode}' and ( `tk_date between` '{$start}' and '{$end}');")or die(mysqli_error());

        /* fetch the fields */
        $fields = mysqli_fetch_fields( $sql );

        /* add each column name to the array */
        foreach( $fields as $field ) {
            $headers[]=$field->name;
        }


        /* establish basic csv formatting parameters */
        $delimiter=',';
        $enclosure='"';

        /* write output to stdout */
        $output=fopen('php://output','w+');
        fputcsv( $output, $headers, $delimiter, $enclosure );

        /* rewind the recordset to begin processing data */
        mysqli_data_seek( $sql, 0 );

        /* process each row - add to stdout */
        while( $row = mysqli_fetch_array( $sql ) ) {
            fputcsv( $output, $row, $delimiter, $enclosure );
        }

        /* close stdout stream */
        fclose( $output );

        /* send the data */
        header("Content-Type: application/csv");   
        header("Content-Disposition: attachment; filename={$filename}");  
        ob_flush();
        exit();
    }

?>