所以我尝试使用 this mysqli 连接类(下面的代码)，但我收到错误消息: fatal error :未定义的类常量 'DBUSER' [...] 我不知道为什么，因为我已经设置了所有数据库连接凭据并包含配置文件。

我的 db.config.class.php:

class config {

    public static $DBSERVER = "localhost"; // Set the IP or hostname of the database server you wish to connect to
    public static $DBNAME = "**REMOVED**"; // Set the name of the database you wish to connect to
    public static $DBUSER = "**REMOVED**"; // set the database user name you wish to use to connect to the database server
    public static $DBPASSWORD = "**REMOVED**"; // set the password for the username above
    public static $DBPORT = 3306;
    public static $TABLEPREFIX = "";

}

mysqli.class.php:

include('db.config.class.php');

/**
 * My-SQL database class
 *
 * @name        mysql
 * @version     2
 * @author      Leigh Edwards
 * @category    PHP
 */

class Dbconnect {

    // leave blank if used for multiple users and call setUser method
    private $sqlUser = "";

    // leave blank if used for multiple users and call setPassword method
    private $sqlPassword = "";

    // set this to the database name you wish to use. If this class is used to access a number of Databases
    // leave blank and call the select method to select the desired database
    private $sqlDatabase = "";

    // set this to the database server address. If you are using this class to connect to differant server
    // leave blank and call the setHost method
    private $sqlHost = "";

    // Set this to the prefix of your tables if you set one while installing.
    // default = ""
    public $table_prefix = "";
    private $result; // Query result
    private $querycount; // Total queries executed
    private $linkid;

    /////////////////////////////////////////END CONFIG OPTIONS/////////////////////////////////////////////////////


    function __construct() {

        $this->loadDefaults ();

        $this->connect ( $this->sqlHost, $this->sqlUser, $this->sqlPassword, $this->sqlDatabase );

        $this->select ( $this->sqlDatabase );


    }

    /*
     * method to load the object with the defaut settings
     */

    private function loadDefaults() {
        $this->sqlUser = config::DBUSER;
        $this->sqlPassword = config::DBPASSWORD;
        $this->sqlHost = config::DBSERVER;
        $this->sqlDatabase = config::DBNAME;
        $this->table_prefix = config::TABLEPREFIX;
    }

    public function getResult() {

        return $this->result;

    }

    /**
     * method to return the prefix for the sql tables
     *
     * @return = string $this->table_prefix
     */

    public function get_tablePrefix() {

        return $this->table_prefix;

    }

    /**
     * function to return a string from within another string
     * found between $beginning and $ending
     *
     * @param string $source
     * @param string $beginning
     * @param string $ending
     * @param string $init_pos
     */

    function get_middle($source, $beginning, $ending, $init_pos) {

        $beginning_pos = strpos ( $source, $beginning, $init_pos );

        $middle_pos = $beginning_pos + strlen ( $beginning );

        $ending_pos = strpos ( $source, $ending, $beginning_pos + 1 );

        $middle = substr ( $source, $middle_pos, $ending_pos - $middle_pos );

        return $middle;

    }

    /**
     * method to connect to the MySQL database server.
     *
     * @param   string  $sqlHost
     * @param   string  $sqlUser
     * @param   string  $sqlPassword
     **/

    function connect($sqlHost, $sqlUser, $sqlPassword, $sqlDatabase) {
        try {
            $this->linkid = mysqli_connect ( $sqlHost, $sqlUser, $sqlPassword, $sqlDatabase, 3306 );
            if (! $this->linkid) {
                die ( 'Connect Error (' . mysqli_connect_errno () . ') ' . mysqli_connect_error () );
            }
        } catch ( Exception $e ) {
            die ( $e->getMessage () );
        }
    }

    /**
     * method to select the database to use
     * @param string $sqlDatabase
     */

    function select($sqlDatabase) {
        try {
            if (! @mysqli_select_db ( $sqlDatabase, $this->linkid )) {
                throw new Exception ( "The Selected Database Can Not Be Found On the Database Server. $sqlDatabase (E2)" );
            }
        } catch ( Exception $e ) {
            die ( $e->getMessage () );
        }
    }

    /**

     * method to query sql database
     * take mysql query string
     * returns false if no results or NULL result is returned by query
     * if query action is not expected to return results eg delete
     * returns false on sucess else returns result set
     *
     * NOTE: If you requier the the actual result set call one of the fetch methods
     *
     * @param string $query
     * @return boolian true or false
     */

    function query($query) {
        // ensure clean results
        unset ( $this->result );
        // make query
        $this->result = mysqli_query ( $query, $this->linkid );
        if (! $this->result) {
            echo "<br>Query faild: $query";
            return FALSE;
        } else {
            return true;
        }
    }

    /**
     * method to return the number of rows affected by the
     * last query exicuted
     * @return int
     */

    function affectedRows() {

        $count = mysqli_affected_rows ( $this->linkid );
        return $count;

    }

    /**
     * method to return the number of rows in the result set
     * returned by the last query
     */

    function numRows() {

        $count = @mysqli_num_rows ( $this->result );

        return $count;

    }

    /**
     * method to return the result row as an object
     * @return  object
     */

    function fetchObject() {

        $row = @mysqli_fetch_object ( $this->result );

        return $row;

    }

    /**
     * method to return the result row as an indexed array
     * @return array
     */

    function fetchRow() {

        $row = @mysqli_fetch_row ( $this->result );

        return $row;

    }

    /**
     * method to return the result row as an associative array.
     * @return array
     **/

    function fetchArray() {

        $row = @mysqli_fetch_array ( $this->result, mysqli_ASSOC );

        return $row;

    }

    /**
     * method to return total number queries executed during
     * the lifetime of this object.
     *
     * @return int
     */

    function numQueries() {

        return $this->querycount;

    }

    function setResult($resultSet) {

        $this->result = $resultSet;

    }

    /**
     * method to return the number of fields in a result set
     * @return int
     **/

    function numberFields() {

        return @mysqli_num_fields ( $this->result );

    }

    /**
     * method to return a field name given an integer offset
     * @return  string
     **/

    function fieldName($offset) {

        return @mysqli_field_name ( $this->result, $offset );

    }

    /**
     * method to return the results of the last query
     * in html table
     *
     * This method uses the $actions string to pass html code
     * this is added to the table to enable display of images or links
     * in the last columb of the table
     *
     * if boolian false is passed no html is add to the result table
     * $startCol sets the col to start displaying 0 being the first
     *
     * @param int $startCol
     * @param string or boolian false $actions
     * @return string containing html code to dispay the table
     */

    function getResultAsTable($startCol, $actions = "") {

        if ($this->numrows () > 0) {

            // Start the table
            $resultHTML = "<table width=\"80%\" border=\"0\" align=\"center\" cellpadding=\"1\" cellspacing=\"0\"><tr>";

            $resultHTML .= "<td><table width=\"100%\" border=\"0\" cellpadding=\"0\" cellspacing=\"1\"><tr>";

            $x = $startCol;

            // Output the table header
            $fieldCount = $this->numberFields ();

            for($i = $x; $i < $fieldCount; $i ++) {

                $rowName = $this->fieldName ( $i );

                $resultHTML .= "<th align=\"left\">$rowName</th>";

            }

            if (! $actions === false) {

                $resultHTML .= "<th align=\"left\">actions</th>";

            }

            $resultHTML .= "</tr>";

            while ( $row = $this->fetchRow () ) {

                $resultHTML .= "<tr>";

                for($i = $x; $i < $fieldCount; $i ++)

                    $resultHTML .= "<td align=\"left\">" . htmlentities ( $row [$i] ) . "</td>";

                if (! $actions === false) {

                    // Replace VALUE with the correct primary key
                    $action = str_replace ( "VALUE", $row [0], $actions );

                    $resultHTML .= "<td nowrap align=\"left\">$action</td>";

                }

                $resultHTML .= "</tr>";

            }

            $resultHTML .= "</table></td></tr></table>";

        } else {

            $resultHTML = "";

        }

        return $resultHTML;

    }

    /**
     * method to retun the value of a given colum using one where clause
     * @param $table
     * @param $col
     * @param $val1
     * @param $col2
     */

    function getRow($table, $col, $val1, $col2) {

        $query = "SELECT '$col2' FROM " . $this->table_prefix . $table . " WHERE $col = '$val1'";

        $this->query ( $query );

        $resultArray = $this->fetchArray ();

        return $resultArray [$col2];

    }

    /**
     * method to test if a row conatining $x in the feild $y exists in the given $table
     * method returns true or false
     * @param $table
     * @param $col
     * @param $val
     * @return boolian
     */

    function rowExistsInDB($table, $col, $val) {
        $this->query ( "SELECT $col FROM '" . $this->table_prefix . $table . "' WHERE '$col' = '$val'" );
        if ($this->numRows () > 0) {
            return true;
        } else {
            return false;
        }
    }

    function rowExistsInDB2($table, $col, $val, $col2, $val2) {

        $query = "SELECT " . $col . " FROM " . $this->table_prefix . $table . " WHERE " . $col . " = '" . mysqli_real_escape_string ( $val ) . "' AND " . $col2 . " = '" . mysqli_real_escape_string ( $val2 ) . "'";
        $this->query ( $query );
        if ($this->numRows () > 0) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * method to delete all rows where $col=$val in $table
     * returns int of number of affected rows or false on fail
     *
     * @param string $table
     * @param string $col
     * @param string $val
     * @return int
     */
    function deleteRow($table, $col, $val) {
        $this->query ( "DELETE FROM '" . $this->table_prefix . $table . "' WHERE '$col' = '$val'" );
        return $this->result;
    }

    // Misc methods to do some convertions and stuff


    // round or pad to 2 decimal points
    function formatNum($num, $dec = 2) {
        for($x = 0; $x <= 5; $x ++) {
            $num = sprintf ( "%01." . ($dec + $x) . "f", $num );
            return $num;
        }
    }
    /**
     * method to reverse the order of a given date
     * and fix to mysql date format
     * so DD/MM/YYYY becomes YYYY-MM-DD
     *
     * @param string $date
     * @return string
     */

    function revDate($date) {

        // first split the date string @ / int o three parts
        $dateArray = explode ( '/', $date, 3 );

        // then reorder them to YYY-MM-DD
        $revDate = array_reverse ( $dateArray );

        $i = 0;

        foreach ( $revDate as $eliment ) {

            $correctDate .= $eliment;

            if ($i < 2) {

                $correctDate .= "-";

            }

            $i ++;

        }

        return $correctDate;

    }

    /**
     * method to revers dates taken from sql database
     * so YYYY-MM-DD becomes DD/MM/YYYY
     *
     * @param string $date
     * @return string
     */

    function revSqlDate($date) {

        // first split the date string @ / int o three parts
        $dateArray = explode ( '-', $date, 3 );

        // then reorder them to DD/MM/YYYY
        $revDate = array_reverse ( $dateArray );

        $i = 0;

        foreach ( $revDate as $eliment ) {

            $correctDate .= $eliment;

            if ($i < 2) {

                $correctDate .= "/";

            }

            $i ++;

        }

        return $correctDate;

    }

}

最佳答案

写成:

config::$DBUSER;

等等

关于php - fatal error : Undefined class constant，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14856075/