Wednesday, March 9, 2011

PHP FTP

PHP FTP Introduction

The FTP functions give client access to file servers through the File Transfer Protocol (FTP).
The FTP functions are used to open, login and close connections, as well as upload, download, rename, delete, and get information on files from file servers. Not all of the FTP functions will work with every server or return the same results. The FTP functions became available with PHP 3.
These functions are meant for detailed access to an FTP server. If you only wish to read from or write to a file on an FTP server, consider using the ftp:// wrapper with the Filesystem functions.

Installation

The windows version of PHP has built-in support for the FTP extension. So, the FTP functions will work automatically.
However, if you are running the Linux version of PHP, you will have to compile PHP with --enable-ftp (PHP 4+) or --with-ftp (PHP 3) to get the FTP functions to work.

PHP FTP Functions

PHP: indicates the earliest version of PHP that supports the function.
Function Description PHP
ftp_alloc() Allocates space for a file to be uploaded to the FTP server 5
ftp_cdup() Changes the current directory to the parent directory on the FTP server 3
ftp_chdir() Changes the current directory on the FTP server 3
ftp_chmod() Sets permissions on a file via FTP 5
ftp_close() Closes an FTP connection 4
ftp_connect() Opens an FTP connection 3
ftp_delete() Deletes a file on the FTP server 3
ftp_exec() Executes a program/command on the FTP server 4
ftp_fget() Downloads a file from the FTP server and saves it to an open file 3
ftp_fput() Uploads from an open file and saves it to a file on the FTP server 3
ftp_get_option() Returns runtime behaviors of the FTP connection 4
ftp_get() Downloads a file from the FTP server 3
ftp_login() Logs on to an FTP connection 3
ftp_mdtm() Returns the last modified time of a specified file 3
ftp_mkdir() Creates a new directory on the FTP server 3
ftp_nb_continue() Continues retrieving/sending a file (non-blocking) 4
ftp_nb_fget() Downloads a file from the FTP server and saves it to an open file (non-blocking) 4
ftp_nb_fput() Uploads from an open file and saves it to a file on the FTP server (non-blocking) 4
ftp_nb_get() Downloads a file from the FTP server (non-blocking) 4
ftp_nb_put() Uploads a file to the FTP server (non-blocking) 4
ftp_nlist() Lists the files in a specified directory on the FTP server 3
ftp_pasv() Turns passive mode on or off 3
ftp_put() Uploads a file to the FTP server 3
ftp_pwd() Returns the current directory name 3
ftp_quit() Alias of ftp_close() 3
ftp_raw() Sends a raw command to the FTP server 5
ftp_rawlist() Returns a detailed list of files in the specified directory 3
ftp_rename() Renames a file or directory on the FTP server 3
ftp_rmdir() Removes a directory on the FTP server 3
ftp_set_option() Sets runtime options for the FTP connection 4
ftp_site() Sends a SITE command to the server 3
ftp_size() Returns the size of the specified file 3
ftp_ssl_connect() Opens a secure SSL-FTP connection 4
ftp_systype() Returns the system type identifier of the FTP server 3


PHP FTP Constants

PHP: indicates the earliest version of PHP that supports the constant.
Constant Description PHP
FTP_ASCII 3
FTP_TEXT 3
FTP_BINARY 3
FTP_IMAGE 3
FTP_TIMEOUT_SEC 3
FTP_AUTOSEEK 4
FTP_AUTORESUME Determine resume position and start position for get and put requests automatically 4
FTP_FAILED Asynchronous transfer has failed 4
FTP_FINISHED Asynchronous transfer has finished 4
FTP_MOREDATA Asynchronous transfer is still active 4

PHP ODBC CONNECTION

ODBC is an Application Programming Interface (API) that allows you to connect to a data source (e.g. an MS Access database).

Create an ODBC Connection

With an ODBC connection, you can connect to any database, on any computer in your network, as long as an ODBC connection is available.
Here is how to create an ODBC connection to a MS Access Database:
  1. Open the Administrative Tools icon in your Control Panel.
  2. Double-click on the Data Sources (ODBC) icon inside.
  3. Choose the System DSN tab.
  4. Click on Add in the System DSN tab.
  5. Select the Microsoft Access Driver. Click Finish.
  6. In the next screen, click Select to locate the database.
  7. Give the database a Data Source Name (DSN).
  8. Click OK.
Note that this configuration has to be done on the computer where your web site is located. If you are running Internet Information Server (IIS) on your own computer, the instructions above will work, but if your web site is located on a remote server, you have to have physical access to that server, or ask your web host to to set up a DSN for you to use.

Connecting to an ODBC

The odbc_connect() function is used to connect to an ODBC data source. The function takes four parameters: the data source name, username, password, and an optional cursor type.
The odbc_exec() function is used to execute an SQL statement.

Example

The following example creates a connection to a DSN called northwind, with no username and no password. It then creates an SQL and executes it:
$conn=odbc_connect('northwind','','');
$sql="SELECT * FROM customers";
$rs=odbc_exec($conn,$sql);


Retrieving Records

The odbc_fetch_row() function is used to return records from the result-set. This function returns true if it is able to return rows, otherwise false.
The function takes two parameters: the ODBC result identifier and an optional row number:
odbc_fetch_row($rs)


Retrieving Fields from a Record

The odbc_result() function is used to read fields from a record. This function takes two parameters: the ODBC result identifier and a field number or name.
The code line below returns the value of the first field from the record:
$compname=odbc_result($rs,1);
The code line below returns the value of a field called "CompanyName":
$compname=odbc_result($rs,"CompanyName");


Closing an ODBC Connection

The odbc_close() function is used to close an ODBC connection.
odbc_close($conn);


An ODBC Example

The following example shows how to first create a database connection, then a result-set, and then display the data in an HTML table.
<html>
<body>

<?php
$conn=odbc_connect('northwind','','');
if (!$conn)
  {exit("Connection Failed: " . $conn);}
$sql="SELECT * FROM customers";
$rs=odbc_exec($conn,$sql);
if (!$rs)
  {exit("Error in SQL");}
echo "<table><tr>";
echo "<th>Companyname</th>";
echo "<th>Contactname</th></tr>";
while (odbc_fetch_row($rs))
  {
  $compname=odbc_result($rs,"CompanyName");
  $conname=odbc_result($rs,"ContactName");
  echo "<tr><td>$compname</td>";
  echo "<td>$conname</td></tr>";
  }
odbc_close($conn);
echo "</table>";
?>

</body>
</html>

PHP MYSQL DELETE

The DELETE statement is used to delete records in a table.

Delete Data In a Database

The DELETE FROM statement is used to delete records from a database table.

Syntax

DELETE FROM table_name
WHERE some_column = some_value

Note: Notice the WHERE clause in the DELETE syntax. The WHERE clause specifies which record or records that should be deleted. If you omit the WHERE clause, all records will be deleted!To learn more about SQL, please visit our SQL tutorial.
To get PHP to execute the statement above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.

Example

Look at the following "Persons" table:
FirstName LastName Age
Peter Griffin 35
Glenn Quagmire 33
The following example deletes all the records in the "Persons" table where LastName='Griffin':
<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("my_db", $con);

mysql_query("DELETE FROM Persons WHERE LastName='Griffin'");

mysql_close($con);
?>
After the deletion, the table will look like this:
FirstName LastName Age
Glenn Quagmire 33

PHP MYSQL UPDATE

The UPDATE statement is used to modify data in a table.

Update Data In a Database

The UPDATE statement is used to update existing records in a table.

Syntax

UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value

Note: Notice the WHERE clause in the UPDATE syntax. The WHERE clause specifies which record or records that should be updated. If you omit the WHERE clause, all records will be updated!To learn more about SQL, please visit our SQL tutorial.
To get PHP to execute the statement above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.

Example

Earlier in the tutorial we created a table named "Persons". Here is how it looks:
FirstName LastName Age
Peter Griffin 35
Glenn Quagmire 33
The following example updates some data in the "Persons" table:
<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("my_db", $con);

mysql_query("UPDATE Persons SET Age = '36'
WHERE FirstName = 'Peter' AND LastName = 'Griffin'");

mysql_close($con);
?>
After the update, the "Persons" table will look like this:
FirstName LastName Age
Peter Griffin 36
Glenn Quagmire 33

PHP WHERE Clause & ORDERBY Keyword

The WHERE clause is used to filter records.

The WHERE clause

The WHERE clause is used to extract only those records that fulfill a specified criterion.

Syntax

SELECT column_name(s)
FROM table_name
WHERE column_name operator value
To learn more about SQL, please visit our SQL tutorial.
To get PHP to execute the statement above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.

Example

The following example selects all rows from the "Persons" table where "FirstName='Peter':
<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("my_db", $con);

$result = mysql_query("SELECT * FROM Persons
WHERE FirstName='Peter'");

while($row = mysql_fetch_array($result))
  {
  echo $row['FirstName'] . " " . $row['LastName'];
  echo "<br />";
  }
?>
The output of the code above will be:
Peter Griffin


The ORDER BY keyword is used to sort the data in a recordset.

The ORDER BY Keyword

The ORDER BY keyword is used to sort the data in a recordset.
The ORDER BY keyword sort the records in ascending order by default.
If you want to sort the records in a descending order, you can use the DESC keyword.

Syntax

SELECT column_name(s)
FROM table_name
ORDER BY column_name(s) ASC|DESC
To learn more about SQL, please visit our SQL tutorial.

Example

The following example selects all the data stored in the "Persons" table, and sorts the result by the "Age" column:
<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("my_db", $con);

$result = mysql_query("SELECT * FROM Persons ORDER BY age");

while($row = mysql_fetch_array($result))
  {
  echo $row['FirstName'];
  echo " " . $row['LastName'];
  echo " " . $row['Age'];
  echo "<br />";
  }

mysql_close($con);
?>
The output of the code above will be:
Glenn Quagmire 33
Peter Griffin 35


Order by Two Columns

It is also possible to order by more than one column. When ordering by more than one column, the second column is only used if the values in the first column are equal:
SELECT column_name(s)
FROM table_name
ORDER BY column1, column2

PHP SELECT

The SELECT statement is used to select data from a database.

Select Data From a Database Table

The SELECT statement is used to select data from a database.

Syntax

SELECT column_name(s)
FROM table_name
To learn more about SQL, please visit our SQL tutorial.
To get PHP to execute the statement above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.

Example

The following example selects all the data stored in the "Persons" table (The * character selects all the data in the table):
<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("my_db", $con);

$result = mysql_query("SELECT * FROM Persons");

while($row = mysql_fetch_array($result))
  {
  echo $row['FirstName'] . " " . $row['LastName'];
  echo "<br />";
  }

mysql_close($con);
?>
The example above stores the data returned by the mysql_query() function in the $result variable.
Next, we use the mysql_fetch_array() function to return the first row from the recordset as an array. Each call to mysql_fetch_array() returns the next row in the recordset. The while loop loops through all the records in the recordset. To print the value of each row, we use the PHP $row variable ($row['FirstName'] and $row['LastName']).
The output of the code above will be:
Peter Griffin
Glenn Quagmire


Display the Result in an HTML Table

The following example selects the same data as the example above, but will display the data in an HTML table:
<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("my_db", $con);

$result = mysql_query("SELECT * FROM Persons");

echo "<table border='1'>
<
tr>
<th>Firstname</th>
<th>Lastname</th>
</tr>";

while($row = mysql_fetch_array($result))
  {
  echo "<tr>";
  echo "<td>" . $row['FirstName'] . "</td>";
  echo "<td>" . $row['LastName'] . "</td>";
  echo "</tr>";
  }
echo "</table>";

mysql_close($con);
?>
The output of the code above will be:
Firstname Lastname
Glenn Quagmire
Peter Griffin

PHP MYSQL INSERT INTO

The INSERT INTO statement is used to insert new records in a table.

Insert Data Into a Database Table

The INSERT INTO statement is used to add new records to a database table.

Syntax

It is possible to write the INSERT INTO statement in two forms.
The first form doesn't specify the column names where the data will be inserted, only their values:
INSERT INTO table_name
VALUES (value1, value2, value3,...)
The second form specifies both the column names and the values to be inserted:
INSERT INTO table_name (column1, column2, column3,...)
VALUES (value1, value2, value3,...)

To learn more about SQL, please visit our SQL tutorial.To get PHP to execute the statements above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.

Example

In the previous chapter we created a table named "Persons", with three columns; "Firstname", "Lastname" and "Age". We will use the same table in this example. The following example adds two new records to the "Persons" table:
<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("my_db", $con);

mysql_query("INSERT INTO Persons (FirstName, LastName, Age)
VALUES ('Peter', 'Griffin', '35')");

mysql_query("INSERT INTO Persons (FirstName, LastName, Age)
VALUES ('Glenn', 'Quagmire', '33')");

mysql_close($con);
?>


Insert Data From a Form Into a Database

Now we will create an HTML form that can be used to add new records to the "Persons" table.
Here is the HTML form:
<html>
<body>

<form action="insert.php" method="post">
Firstname: <input type="text" name="firstname" />
Lastname: <input type="text" name="lastname" />
Age: <input type="text" name="age" />
<input type="submit" />
</form>

</body>
</html>
When a user clicks the submit button in the HTML form in the example above, the form data is sent to "insert.php".
The "insert.php" file connects to a database, and retrieves the values from the form with the PHP $_POST variables.
Then, the mysql_query() function executes the INSERT INTO statement, and a new record will be added to the "Persons" table.
Here is the "insert.php" page:
<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("my_db", $con);

$sql="INSERT INTO Persons (FirstName, LastName, Age)
VALUES
('$_POST[firstname]','$_POST[lastname]','$_POST[age]')";

if (!mysql_query($sql,$con))
  {
  die('Error: ' . mysql_error());
  }
echo "1 record added";

mysql_close($con)
?>