root/db.php

<?php

require_once "config.php";

function db_connect($host, $user, $pass, $db) {
    if (DB_TYPE == "pgsql") {    
              
        $string = "dbname=$db user=$user password=$pass";    
        
        if ($host) {
            $string .= " host=$host";
        }

        if (defined('DB_PORT')) {
            $string = "$string port=" . DB_PORT;
        }

        $link = pg_connect($string);

        if (!$link) {
            die("Connection failed: " . pg_last_error($link));
        }

        return $link;

    } else if (DB_TYPE == "mysql") {
        $link = mysql_connect($host, $user, $pass);
        if ($link) {
            $result = mysql_select_db($db, $link);            
            if (!$result) {
                die("Can't select DB: " . mysql_error($link));
            }            
            return $link;
        } else {
            die("Connection failed: " . mysql_error($link));
        }
    }
}

function db_escape_string($s) {
    if (DB_TYPE == "pgsql") {    
        return pg_escape_string($s);
    } else {
        return mysql_real_escape_string($s);
    }
}

/* I hate MySQL :( */

function db_escape_string_2($s, $link) {
    if (DB_TYPE == "pgsql") {    
        return pg_escape_string($s);
    } else {
        return mysql_real_escape_string($s, $link);
    }
}

function db_query($link, $query, $die_on_error = true) {
    if (DB_TYPE == "pgsql") {
        $result = pg_query($link, $query);
        if (!$result) {
            $query = htmlspecialchars($query); // just in case
            if ($die_on_error) {
                die("Query <i>$query</i> failed [$result]: " . pg_last_error($link));            
            }
        }
        return $result;
    } else if (DB_TYPE == "mysql") {
        $result = mysql_query($query, $link);
        if (!$result) {
            $query = htmlspecialchars($query);
            if ($die_on_error) {
                die("Query <i>$query</i> failed: " . mysql_error($link));
            }
        }
        return $result;
    }
}

function db_query_2($query) {
    if (DB_TYPE == "pgsql") {
        return pg_query($query);
    } else if (DB_TYPE == "mysql") {
        return mysql_query($link);
    }
}

function db_fetch_assoc($result) {
    if (DB_TYPE == "pgsql") {
        return pg_fetch_assoc($result);
    } else if (DB_TYPE == "mysql") {
        return mysql_fetch_assoc($result);
    }
}


function db_num_rows($result) {
    if (DB_TYPE == "pgsql") {
        return pg_num_rows($result);
    } else if (DB_TYPE == "mysql") {
        return mysql_num_rows($result);
    }
}

function db_fetch_result($result, $row, $param) {
    if (DB_TYPE == "pgsql") {
        return pg_fetch_result($result, $row, $param);
    } else if (DB_TYPE == "mysql") {
        // I hate incoherent naming of PHP functions
        return mysql_result($result, $row, $param);
    }
}

function db_unescape_string($str) {
    $tmp = str_replace("\\\"", "\"", $str);
    $tmp = str_replace("\\'", "'", $tmp);
    return $tmp;
}

function db_close($link) {
    if (DB_TYPE == "pgsql") {

        return pg_close($link);

    } else if (DB_TYPE == "mysql") {
        return mysql_close($link);
    }
}

function db_affected_rows($link, $result) {
    if (DB_TYPE == "pgsql") {
        return pg_affected_rows($result);
    } else if (DB_TYPE == "mysql") {
        return mysql_affected_rows($link);
    }
}

function db_last_error($link) {
    if (DB_TYPE == "pgsql") {
        return pg_last_error($link);
    } else if (DB_TYPE == "mysql") {
        return mysql_error($link);
    }
}

?>