I know it's an old question, but here is another solution:
This duplicates a row in the main table, assuming the primary key is auto-increment, and creates copies of linked-tables data with the new main table id.
Other options for getting column names:
-SHOW COLUMNS FROM tablename; (Column name: Field)
-DESCRIBE tablename           (Column name: Field)
-SELECT column_name FROM information_schema.columns WHERE table_name = 'tablename'   (Column name: column_name)
//First, copy main_table row
$ColumnHdr='';
$Query="SHOW COLUMNS FROM `main_table`;";
$Result=Wrappedmysql_query($Query,$link,__FILE__,__LINE__);
while($Row=mysql_fetch_array($Result))
{
    if($Row['Field']=='MainTableID')     //skip main table id in column list
        continue;
    $ColumnHdr.=",`" . $Row['Field'] . "`";
}
$Query="INSERT INTO `main_table` (" . substr($ColumnHdr,1) . ")
        (SELECT " . substr($ColumnHdr,1) . " FROM `main_table`
            WHERE `MainTableID`=" . $OldMainTableID . ");";
$Result=Wrappedmysql_query($Query,$link,__FILE__,__LINE__);
$NewMainTableID=mysql_insert_id($link);
//Change the name (assumes a 30 char field)
$Query="UPDATE `main_table` SET `Title`=CONCAT(SUBSTRING(`Title`,1,25),' Copy') WHERE `MainTableID`=" . $NewMainTableID . ";";
$Result=Wrappedmysql_query($Query,$link,__FILE__,__LINE__);
//now copy in the linked tables
$TableArr=array("main_table_link1","main_table_link2","main_table_link3");
foreach($TableArr as $TableArrK=>$TableArrV)
{
    $ColumnHdr='';
    $Query="SHOW COLUMNS FROM `" . $TableArrV . "`;";
    $Result=Wrappedmysql_query($Query,$link,__FILE__,__LINE__);
    while($Row=mysql_fetch_array($Result))
    {
        if($Row['Field']=='MainTableID')     //skip main table id in column list, re-added in query
            continue;
        if($Row['Field']=='dbID')    //skip auto-increment,primary key in linked table
            continue;
        $ColumnHdr.=",`" . $Row['Field'] . "`";
    }
    $Query="INSERT INTO `" . $TableArrV . "` (`MainTableID`," . substr($ColumnHdr,1) . ")
            (SELECT " . $NewMainTableID . "," . substr($ColumnHdr,1) . " FROM `" . $TableArrV . "`
             WHERE `MainTableID`=" . $OldMainTableID . ");";
    $Result=Wrappedmysql_query($Query,$link,__FILE__,__LINE__);
}