In PHP, how can timestamps be generated from regular date values and cause issues in SQL queries?

When generating timestamps from regular date values in PHP, it is important to ensure that the date format is compatible with SQL queries. One common issue arises when the date format used in PHP does not match the format expected by the SQL database, leading to errors or unexpected results in queries. To solve this issue, it is recommended to use the `strtotime()` function in PHP to convert the date value to a Unix timestamp, which can be easily inserted into SQL queries.

$date = "2022-01-15";
$timestamp = strtotime($date);
$sql = "INSERT INTO table_name (timestamp_column) VALUES ('$timestamp')";
// Execute the SQL query with the timestamp value