Importing tables structures and data using php

importing-db.php

<?php
/**
 * Importing  tables structures and data using php
 */ 
function backup_database( $tables = '*' ){
try{
   $conn = mysqli_connect($host_name, $username, $password, $dbname);
		//get all of the tables
			if($tables == '*') {
				$tables = array();
				$result = mysqli_query( $conn , 'SHOW TABLES' );
				while($row = mysqli_fetch_row($result)) {
					$tables[] = $row[0];
				}
			} else {
				$tables = is_array($tables) ? $tables : explode(',',$tables);
			}
			
			//cycle through
			$return = '';
			foreach($tables as $table) {
				$result =  mysqli_query( $conn ,'SELECT * FROM '.$table );
				$num_fields = mysqli_num_fields($result);
				
				$return.= 'DROP TABLE IF EXISTS `'.$table.'`;';
				$row2 = mysqli_fetch_row(  mysqli_query( $conn ,'SHOW CREATE TABLE `'.$table.'`' ) );
				$return.= "\n\n".$row2[1].";\n\n";
				
				for ($i = 0; $i < $num_fields; $i++) {
					while($row = mysqli_fetch_row($result)) {
						
						$return.= "INSERT INTO `".$table."` VALUES(";
						
						for($j=0; $j < $num_fields; $j++) {
							$row[$j] = mysqli_real_escape_string( $conn, $row[$j] );
							// $row[$j] = preg_replace( "/\n/i","\\n",$row[$j] );
							// $row[$j] = preg_replace( "/\n/i","\\n",$row[$j] );


							if (isset($row[$j])) { $return.= "'".$row[$j]."'" ; } else { $return.= "''"; }
							if ($j < ($num_fields-1)) { $return.= ","; }
						}

						$return.= ");\n";
					}
				}
				$return.="\n\n\n";
			}
			
			//save file

			$handle = fopen('backup/sql/db-backup-'.date('Y-m-d').'.sql','w+');
			fwrite($handle,$return);
			fclose($handle);
			// sql generated successfully	
			echo "sql";

		} catch ( Exception $e ){
			// catch message
			// unable to generate
		}
}
?>