插入php数组并导出到txt会创建重复值

Question

The following script produces the txt file with the required data, but it produces the data twice in the text file.

 mysql_connect($hostname_MySQLCon, $username_MySQLCon, "") or die(mysql_error()); 
 mysql_select_db($database_MySQLCon) or die(mysql_error()); 
 $data = mysql_query("
    SELECT sales_flat_order.increment_id, sales_flat_order.gift_message_id, sales_flat_order.status, gift_message.gift_message_id, gift_message.message
    FROM sales_flat_order
    JOIN gift_message ON sales_flat_order.gift_message_id = gift_message.gift_message_id
    WHERE sales_flat_order.gift_message_id IS NOT NULL
    GROUP BY sales_flat_order.increment_id
    /* AND sales_flat_order.status = 'pending' */;") 
 or die(mysql_error());  
 while($result = mysql_fetch_array( $data )) 
 { 
    $dataRow[] = implode("|", $result);
 } 
$theFile = 'orders-meta.txt';
if (!$handle = fopen($theFile, 'a')) {
    exit;}
if (fwrite($handle, implode("
", $dataRow)) === FALSE) {
    echo "Cannot write to file ($theFile)";
exit;}
echo "Success, the file was written.";
fclose($handle);

Example output in the txt file:

100000001|100000001|1121|1121|pending|pending|1121|gift message|gift message
100000002|100000002|1123|1123|pending|pending|1123|Gift message|Gift message

Why would it be producing each value twice? And how can I change it so that output would be:

100000001|1121|pending|1121|gift message
100000002|1123|pending|1123|Gift message

Really appreciate any help.

Thanks

Answer 1

From the docs:

Returns an array of strings that corresponds to the fetched row, or FALSE if there are no more rows. The type of returned array depends on how result_type is defined. By using MYSQL_BOTH (default), you'll get an array with both associative and number indices. Using MYSQL_ASSOC, you only get associative indices (as mysql_fetch_assoc() works), using MYSQL_NUM, you only get number indices (as mysql_fetch_row() works).

mysql_fetch_array fetches each result twice, once as an assoc array, once as a numerically indexed array by default. That's why you get duplicate rows.

Having said that, please don't use mysql_* as it's in the deprecation process, read the read box on the doc pages, and click on the links to PDO or mysqli_*, or the links here and here