PHPExcel | while循环内的while循环无法正常工作

Question

I have some SQL data that I want to pass to an Excel document using PHPExcel.

There are 3 tables:

1. Books:

   1.1 bookID

   1.2 bookName

2. Tags:

   2.1 tagID

   2.2 tagName

3. Post_Tags:

   3.1 id

   3.2 tagID

   3.3 bookID

I want the tags to be in the second column of the xls sheet, seperated by commas. So here I have a while loop inside a while loop.

The problem:

In the produced excel sheet, not all the book's tags are listed in each column B's cell, but only a single tag.

Any ideas why? Thanks in advance :)

require_once "includes/config.php";
require_once "includes/functions.php";
require_once 'phptoxls/PHPExcel.php';

// Create new PHPExcel object
$objPHPExcel = new PHPExcel();
$F = $objPHPExcel -> getActiveSheet();


/*      START: RECORDS      */

$line = 2;
$query = mysql_query('SELECT * FROM `books`') or die(mysql_error());
while($row = mysql_fetch_assoc($query)){

$bookID = $row['bookID'];
$bookName = $row['bookName'];

$query2 = mysql_query('SELECT * FROM `books`
                    INNER JOIN `post_tags`
                    ON post_tags.bookID = books.bookID
                    INNER JOIN `tags`
                    ON tags.tagID = post_tags.tagID
                    WHERE books.bookID = "'.$bookID.'"') or die(mysql_error());

if(mysql_num_rows($query2) > 0){
    $rowNum = mysql_num_rows($query2);
    $i = 1;
    while($row1 = mysql_fetch_assoc($query2)){
        $tags = $row1['tagName'];
        if($i < $rowNum){
            $tags .= ', ';
        }
    }
}

    $F  -> setCellValue('A'.$line, $bookName)
        -> setCellValue('B'.$line, $tags);

    ++$line;
}

/*      END: RECORDS        */


// Redirect output to a client’s web browser (Excel5)
header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment;filename="books.xls');
header('Cache-Control: max-age=0');

$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
$objWriter->save('php://output');
exit;

Answer 1

Here lies your issue:

while($row1 = mysql_fetch_assoc($query2)){
    $tags = $row1['tagName'];

You are resetting the value of $tags with every loop. To get it working with the code you supplied simply do the following:

if(mysql_num_rows($query2) > 0){
    $rowNum = mysql_num_rows($query2);
    $i = 1;
    $tags = "";
    while($row1 = mysql_fetch_assoc($query2)){
        $tags .= $row1['tagName'];
        if($i < $rowNum){
            $tags .= ', ';
        }
    }
}

I would however suggest you fix it by doing this:

if(mysql_num_rows($query2) > 0){
    while($row1 = mysql_fetch_assoc($query2)){
        $tags[] = $row1['tagName'];
    }
    $tags = implode(', ',$tags);
}

Answer 2

First of all please indent your code better, because it's almost unreadable( http://beta.phpformatter.com ). Second: I think you just concatenating the tags with ','-s. Dude seriously at the beginning of your 1st while:

<?php
require_once "includes/config.php";
require_once "includes/functions.php";
require_once 'phptoxls/PHPExcel.php';

// Create new PHPExcel object
$objPHPExcel = new PHPExcel();
$F = $objPHPExcel->getActiveSheet();


/*      START: RECORDS      */

$line = 2;
$query = mysql_query('SELECT * FROM `books`') or die(mysql_error());
while ($row = mysql_fetch_assoc($query)) {
    $all_tags_for_one_row = '';
    $bookID = $row['bookID'];
    $bookName = $row['bookName'];

    $query2 = mysql_query('SELECT * FROM `books`
                    INNER JOIN `post_tags`
                    ON post_tags.bookID = books.bookID
                    INNER JOIN `tags`
                    ON tags.tagID = post_tags.tagID
                    WHERE books.bookID = "' . $bookID . '"') or die(mysql_error());

    if (mysql_num_rows($query2) > 0) {
        $rowNum = mysql_num_rows($query2);
        $i = 1;
        while ($row1 = mysql_fetch_assoc($query2)) {
            $tags = $row1['tagName'];
            if ($i < $rowNum) {

                $all_tags_for_one_row .= ($i != $rowNum ? $tags . ', ' : $tags ); 
            }
            $i++;
        }
    }

    $F->setCellValue('A' . $line, $bookName);
    $F->setCellValue('B' . $line, $all_tags_for_one_row);

    ++$line;
}

/*      END: RECORDS        */


// Redirect output to a client’s web browser (Excel5)
header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment;filename="books.xls');
header('Cache-Control: max-age=0');

$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
$objWriter->save('php://output');
exit;
?>