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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);
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Retrieving Records
The odbc_fetch_rows() 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:
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);
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The code line below returns the value of a field called
"CompanyName":
$compname=odbc_result($rs,"CompanyName");
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Closing an ODBC Connection
The odbc_close() function is used to close an ODBC
connection.
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>
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