SQL命令分为多个php行

I have to split up this SQL command and now I have a problem with the gazillion number of quotation marks. Can someone please help?? (I'm trying to dynamically assign a filename to the OUTFILE which must include a current timestamp as part of the filename). Thanks.

<?php 

  $sql_query = "SELECT @myCommand := concat("'SELECT UNIX_TIMESTAMP( TIMESTAMP( CURDATE( ) , HalfHourTime ) ), 0, 0, 0, 0 '";
  $sql_query =$sql_query . into OUTFILE 'C:/wamp/www/myApp/services/csv/filename-", 'DATE_FORMAT(now(),"%Y%m%d-%H%i%s")', '.csv' "' ';
  $sql_query =$sql_query . FIELDS TERMINATED BY ','  ';
  $sql_query =$sql_query . LINES TERMINATED BY '
'';
  $sql_query =$sql_query .FROM timeintervals_halfhours';
  $sql_query =$sql_query . ');";
  $sql_query =$sql_query . "PREPARE stmt FROM @myCommand; ";
  $sql_query =$sql_query . "EXECUTE stmt;";

  define("DATABASE_SERVER", "localhost");
  define("DATABASE_USERNAME", "root");
  define("DATABASE_PASSWORD", "");
  define("DATABASE_NAME", "dataR");

  $con = mysqli_connect(DATABASE_SERVER, DATABASE_USERNAME, DATABASE_PASSWORD, DATABASE_NAME);
  $selected_db = mysql_select_db(DATABASE_NAME, $con);     

  $result = mysql_query($sql_query);

  $temp = mysql_fetch_array($result);
?>

Instead of doing the $sql = $sql . "more", you can concatenate your strings by using .= instead, like this

$sql .= 'more';

You also have a issue in your line of SQL, where you're doing something wrong with a quote, what do you want to do with it? Escape it?

$sql_query = "SELECT @myCommand := concat("'SELECT UNIX_TIMESTAMP( TIMESTAMP( CURDATE( ) , HalfHourTime ) ), 0, 0, 0, 0 '";
                                          ^

For this particular query, i would recommend you build your SQL with heredoc, as you do not need to escape stuff with it

You might want to investigate using PHP mysqli::prepare statements, to avoid this kind of string manipulation. See http://www.php.net/manual/en/mysqli.prepare.php for details.

Don't split anything, whitespace is your friend (especially with an 8 character lead, and indentation increments of 4)

$sql = 'SELECT *
        FROM `table`
        WHERE `table`.`field` = :param';

And as recommended, use prepared statements; transition to PDO.