ini_set("max_execution_time", "180");//避免数据量过大，导出不全的情况出现。 

$host="";//数据库地址 

$dbname="";//这里配置数据库名 

$username="";//用户名 

$passw="";//这里配置密码 

$filename=date("Y-m-d_H-i-s")."-".$dbname.".sql"; 
header("Content-disposition:filename=".$filename);//所保存的文件名 
header("Content-type:application/octetstream"); 
header("Pragma:no-cache"); 
header("Expires:0"); 

//备份数据 
$i = 0; 
$crlf="\r\n"; 
global $dbconn; 
$dbconn = mysql_connect($host,$username,$passw);//数据库主机，用户名，密码 
$db = mysql_select_db($dbname,$dbconn); 
mysql_query("SET NAMES 'utf8'"); 
$tables =mysql_list_tables($dbname,$dbconn); 
$num_tables = @mysql_num_rows($tables); 
print "-- filename=".$filename; 
while($i < $num_tables) 
{ 
$table=mysql_tablename($tables,$i); 
print $crlf; 
echo get_table_structure($dbname, $table, $crlf).";$crlf$crlf"; 
//echo get_table_def($dbname, $table, $crlf).";$crlf$crlf"; 
echo get_table_content($dbname, $table, $crlf); 
$i++; 
} 

/*新增的获得详细表结构*/ 
function get_table_structure($db,$table,$crlf) 
{ 
global $drop; 

$schema_create = ""; 
if(!empty($drop)){ $schema_create .= "DROP TABLE IF EXISTS `$table`;$crlf";} 
$result =mysql_db_query($db, "SHOW CREATE TABLE $table"); 
$row=mysql_fetch_array($result); 
$schema_create .= $crlf."-- ".$row[0].$crlf; 
$schema_create .= $row[1].$crlf; 
Return $schema_create; 
} 

function get_table_content($db, $table, $crlf) 
{ 
$schema_create = ""; 
$temp = ""; 
$result = mysql_db_query($db, "SELECT * FROM $table"); 
$i = 0; 
while($row = mysql_fetch_row($result)) 
{ 
$schema_insert = "INSERT INTO `$table` VALUES ("; 
for($j=0; $j