- preg_match: documentation ( source)
- print_r: documentation ( source)
- preg_replace: documentation ( source)
<?php
$matches = array();
$param_string = "CREATED_AT > TO_DATE(:delete_date, 'DD/MM/YYYY HH24:MI:SS') AND";
$regex = '/[^A-Za-z](:\b[^\s:]+)\b[^:]/i';
$repl = '\1';
$param = preg_replace($regex, $repl, $param_string);
print "$param\n";
$param = preg_match($regex, $param_string, $matches);
print_r($matches);