Apostrophes (also known as single quotes) can cause problems when writing text into a MySQL database, as they are often used to enclose strings and can be misinterpreted as the beginning or ending of a string. To correctly handle apostrophes in MySQL, you can use one of the following methods:

1. Escape the apostrophe: You can escape the apostrophe by adding a backslash before it, like this: \'. This tells MySQL to treat the apostrophe as a literal character rather than as the beginning or ending of a string.

$text = "O\'Reilly";
$query = "INSERT INTO table (column) VALUES ('$text')";
mysqli_query($link, $query);

2. Use double quotes: You can also enclose strings in double quotes (") instead of single quotes ('). Double quotes allow you to use variables and escape sequences within the string, while single quotes do not.

$text = "O'Reilly";
$query = "INSERT INTO table (column) VALUES (\"$text\")";
mysqli_query($link, $query);

3. Use a prepared statement: Prepared statements allow you to separate the SQL code from the data being provided by the user, which can help to prevent errors and security vulnerabilities such as SQL injection. You can use a prepared statement to insert text into a MySQL database, like this:

$text = "O'Reilly";
$stmt = mysqli_prepare($link, "INSERT INTO table (column) VALUES (?)");
mysqli_stmt_bind_param($stmt, "s", $text);
mysqli_stmt_execute($stmt);

By using one of these methods, you can correctly handle apostrophes in MySQL and avoid errors when inserting text into a database. It is important to properly handle special characters such as apostrophes, as they can cause problems if they are not handled correctly.