PHP MySQL Update
The UPDATE statement is used to modify data in a table
The MySQL UPDATE Statement
In this chapter we will show you how to change data in a table.In PHP this is done the same way as a table or database is created. The MySQL syntax is sent to the server with the mysql_query() function.
Updating Data In a Database
Earlier in the tutorial we created a table named "Person", with three columns. We will use the same table in this example.
FirstName
|
LastName
|
Age
|
Peter
|
Griffin
|
35
|
Glenn
|
Quagmire
|
33
|
MySQL Syntax
UPDATE table_name
SET column_name = new_value
WHERE column_name = some_value
|
Now we use this together with the mysql_query() function.
Example
This code updates data in the "Person" 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 Person SET Age = '40'
WHERE LastName = 'Griffin'");
?>
|
FirstName
|
LastName
|
Age
|
Peter
|
Griffin
|
40
|
Glenn
|
Quagmire
|
PHP MySQL Delete
The DELETE statement is used delete rows in a table
The MySQL DELETE Statement
In this chapter we will show you how to delete rows from a table.In PHP this is done the same way as a table or database is created. The MySQL syntax is sent to the server with the mysql_query() function.
Deleting Data In a Database
Earlier in the tutorial we created a table named "Person", with three columns. We will use the same table in this example.
FirstName
|
LastName
|
Age
|
Peter
|
Griffin
|
35
|
Glenn
|
Quagmire
|
33
|
MySQL Syntax
DELETE FROM table_name
WHERE column_name = some_value
|
Now we use this together with the mysql_query() function.
Example
This code updates data in the "Person" table:<?php
$con = mysql_connect("localhost","peter","abc123");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_select_db("my_db", $con);
mysql_query("DELETE FROM Person
WHERE LastName = 'Griffin'");
?>
|
FirstName
|
LastName
|
Age
|
Glenn
|
Quagmire
|
33
|
PHP Database ODBC
Create an ODBC Connection
With an ODBC connection, you can connect to any database, on any computer in your network, as long as an ODBC connection is available.Here is how to create an ODBC connection to a MS Access Database:
- Open the Administrative Tools icon in your Control Panel.
- Double-click on the Data Sources (ODBC) icon inside.
- Choose the System DSN tab.
- Click on Add in the System DSN tab.
- Select the Microsoft Access Driver. Click Finish.
- In the next screen, click Select to locate the database.
- Give the database a Data Source Name (DSN).
- Click OK.
Connecting to an ODBC
The odbc_connect() function is used to connect to an ODBC data source. The function takes four parameters: the data source name, username, password, and an optional cursor type.The odbc_exec() function is used to execute an SQL statement.
Example
The following example creates a connection to a DSN called northwind, with no username and no password. It then creates an SQL and executes it:$conn=odbc_connect('northwind','','');
$sql="SELECT * FROM customers";
$rs=odbc_exec($conn,$sql);
|
Retrieving Records
The odbc_fetch_rows() function is used to return records from the result-set. This function returns true if it is able to return rows, otherwise false.
The function takes two parameters: the ODBC result identifier and an optional row number:
odbc_fetch_row($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);
|
$compname=odbc_result($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>
|
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