Dhaval Thummar (dp)

PHP Database ODBC

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:

Open the Administrative Tools icon in your Control Panel.
Double-click on the Data Sources (ODBC) icon inside.
Choose the System DSN tab.
Click on Add in the System DSN tab.
Select the Microsoft Access Driver. Click Finish.
In the next screen, click Select to locate the database.
Give the database a Data Source Name (DSN).
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 mysqli_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=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

mysqli_query($con,"DELETE FROM Persons WHERE LastName='Griffin'");

mysqli_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 mysqli_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=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

mysqli_query($con,"UPDATE Persons SET Age=36
WHERE FirstName='Peter' AND LastName='Griffin'");

mysqli_close($con);
?>

After the update, the "Persons" table will look like this:

FirstName	LastName	Age
Peter	Griffin	36
Glenn	Quagmire	33

PHP MySQL Order By Keyword

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=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

$result = mysqli_query($con,"SELECT * FROM Persons ORDER BY age");

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

mysqli_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 MySQL The Where Clause

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 mysqli_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=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

$result = mysqli_query($con,"SELECT * FROM Persons
WHERE FirstName='Peter'");

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

The output of the code above will be:

Peter Griffin

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=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

$result = mysqli_query($con,"SELECT * FROM Persons");

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

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

echo "</table>";

mysqli_close($con);
?>

The output of the code above will be:

Firstname	Lastname
Glenn	Quagmire
Peter	Griffin

Dhaval Thummar (dp)

Pages

Friday, 13 June 2014

Welcome

PHP Database ODBC

Create an ODBC Connection

Connecting to an ODBC

Example

Retrieving Records

Retrieving Fields from a Record

Closing an ODBC Connection

An ODBC Example

PHP MySQL Delete

Delete Data In a Database

Syntax

Example

PHP MySQL Update

Update Data In a Database

Syntax

Example

PHP MySQL Order By Keyword

The ORDER BY Keyword

Syntax

Example

Order by Two Columns

PHP MySQL The Where Clause

The WHERE clause

Syntax

Example

Display the Result in an HTML Table