mysql.php

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

     * @see DB_common::dropSequence(), DB_common::getSequenceName(),
     *      DB_mysql::nextID(), DB_mysql::createSequence()
     */
    function dropSequence($seq_name)
    {
        return $this->query('DROP TABLE ' . $this->getSequenceName($seq_name));
    }

    // }}}
    // {{{ _BCsequence()

    /**
     * Backwards compatibility with old sequence emulation implementation
     * (clean up the dupes)
     *
     * @param string $seqname  the sequence name to clean up
     *
     * @return bool  true on success.  A DB_Error object on failure.
     *
     * @access private
     */
    function _BCsequence($seqname)
    {
        // Obtain a user-level lock... this will release any previous
        // application locks, but unlike LOCK TABLES, it does not abort
        // the current transaction and is much less frequently used.
        $result = $this->getOne("SELECT GET_LOCK('${seqname}_lock',10)");
        if (DB::isError($result)) {
            return $result;
        }
        if ($result == 0) {
            // Failed to get the lock, can't do the conversion, bail
            // with a DB_ERROR_NOT_LOCKED error
            return $this->mysqlRaiseError(DB_ERROR_NOT_LOCKED);
        }

        $highest_id = $this->getOne("SELECT MAX(id) FROM ${seqname}");
        if (DB::isError($highest_id)) {
            return $highest_id;
        }
        // This should kill all rows except the highest
        // We should probably do something if $highest_id isn't
        // numeric, but I'm at a loss as how to handle that...
        $result = $this->query('DELETE FROM ' . $seqname
                               . " WHERE id <> $highest_id");
        if (DB::isError($result)) {
            return $result;
        }

        // If another thread has been waiting for this lock,
        // it will go thru the above procedure, but will have no
        // real effect
        $result = $this->getOne("SELECT RELEASE_LOCK('${seqname}_lock')");
        if (DB::isError($result)) {
            return $result;
        }
        return true;
    }

    // }}}
    // {{{ quoteIdentifier()

    /**
     * Quotes a string so it can be safely used as a table or column name
     *
     * MySQL can't handle the backtick character (<kbd>`</kbd>) in
     * table or column names.
     *
     * @param string $str  identifier name to be quoted
     *
     * @return string  quoted identifier string
     *
     * @see DB_common::quoteIdentifier()
     * @since Method available since Release 1.6.0
     */
    function quoteIdentifier($str)
    {
        return '`' . $str . '`';
    }

    // }}}
    // {{{ quote()

    /**
     * @deprecated  Deprecated in release 1.6.0
     */
    function quote($str)
    {
        return $this->quoteSmart($str);
    }

    // }}}
    // {{{ escapeSimple()

    /**
     * Escapes a string according to the current DBMS's standards
     *
     * @param string $str  the string to be escaped
     *
     * @return string  the escaped string
     *
     * @see DB_common::quoteSmart()
     * @since Method available since Release 1.6.0
     */
    function escapeSimple($str)
    {
        if (function_exists('mysql_real_escape_string')) {
            return @mysql_real_escape_string($str, $this->connection);
        } else {
            return @mysql_escape_string($str);
        }
    }

    // }}}
    // {{{ modifyQuery()

    /**
     * Changes a query string for various DBMS specific reasons
     *
     * This little hack lets you know how many rows were deleted
     * when running a "DELETE FROM table" query.  Only implemented
     * if the DB_PORTABILITY_DELETE_COUNT portability option is on.
     *
     * @param string $query  the query string to modify
     *
     * @return string  the modified query string
     *
     * @access protected
     * @see DB_common::setOption()
     */
    function modifyQuery($query)
    {
        if ($this->options['portability'] & DB_PORTABILITY_DELETE_COUNT) {
            // "DELETE FROM table" gives 0 affected rows in MySQL.
            // This little hack lets you know how many rows were deleted.
            if (preg_match('/^\s*DELETE\s+FROM\s+(\S+)\s*$/i', $query)) {
                $query = preg_replace('/^\s*DELETE\s+FROM\s+(\S+)\s*$/',
                                      'DELETE FROM \1 WHERE 1=1', $query);
            }
        }
        return $query;
    }

    // }}}
    // {{{ modifyLimitQuery()

    /**
     * Adds LIMIT clauses to a query string according to current DBMS standards
     *
     * @param string $query   the query to modify
     * @param int    $from    the row to start to fetching (0 = the first row)
     * @param int    $count   the numbers of rows to fetch
     * @param mixed  $params  array, string or numeric data to be used in
     *                         execution of the statement.  Quantity of items
     *                         passed must match quantity of placeholders in
     *                         query:  meaning 1 placeholder for non-array
     *                         parameters or 1 placeholder per array element.
     *
     * @return string  the query string with LIMIT clauses added
     *
     * @access protected
     */
    function modifyLimitQuery($query, $from, $count, $params = array())
    {
        if (DB::isManip($query)) {
            return $query . " LIMIT $count";
        } else {
            return $query . " LIMIT $from, $count";
        }
    }

    // }}}
    // {{{ mysqlRaiseError()

    /**
     * Produces a DB_Error object regarding the current problem
     *
     * @param int $errno  if the error is being manually raised pass a
     *                     DB_ERROR* constant here.  If this isn't passed
     *                     the error information gathered from the DBMS.
     *
     * @return object  the DB_Error object
     *
     * @see DB_common::raiseError(),
     *      DB_mysql::errorNative(), DB_common::errorCode()
     */
    function mysqlRaiseError($errno = null)
    {
        if ($errno === null) {
            if ($this->options['portability'] & DB_PORTABILITY_ERRORS) {
                $this->errorcode_map[1022] = DB_ERROR_CONSTRAINT;
                $this->errorcode_map[1048] = DB_ERROR_CONSTRAINT_NOT_NULL;
                $this->errorcode_map[1062] = DB_ERROR_CONSTRAINT;
            } else {
                // Doing this in case mode changes during runtime.
                $this->errorcode_map[1022] = DB_ERROR_ALREADY_EXISTS;
                $this->errorcode_map[1048] = DB_ERROR_CONSTRAINT;
                $this->errorcode_map[1062] = DB_ERROR_ALREADY_EXISTS;
            }
            $errno = $this->errorCode(mysql_errno($this->connection));
        }
        return $this->raiseError($errno, null, null, null,
                                 @mysql_errno($this->connection) . ' ** ' .
                                 @mysql_error($this->connection));
    }

    // }}}
    // {{{ errorNative()

    /**
     * Gets the DBMS' native error code produced by the last query
     *
     * @return int  the DBMS' error code
     */
    function errorNative()
    {
        return @mysql_errno($this->connection);
    }

    // }}}
    // {{{ tableInfo()

    /**
     * Returns information about a table or a result set
     *
     * @param object|string  $result  DB_result object from a query or a
     *                                 string containing the name of a table.
     *                                 While this also accepts a query result
     *                                 resource identifier, this behavior is
     *                                 deprecated.
     * @param int            $mode    a valid tableInfo mode
     *
     * @return array  an associative array with the information requested.
     *                 A DB_Error object on failure.
     *
     * @see DB_common::tableInfo()
     */
    function tableInfo($result, $mode = null)
    {
        if (is_string($result)) {
            /*
             * Probably received a table name.
             * Create a result resource identifier.
             */
            $id = @mysql_list_fields($this->dsn['database'],
                                     $result, $this->connection);
            $got_string = true;
        } elseif (isset($result->result)) {
            /*
             * Probably received a result object.
             * Extract the result resource identifier.
             */
            $id = $result->result;
            $got_string = false;
        } else {
            /*
             * Probably received a result resource identifier.
             * Copy it.
             * Deprecated.  Here for compatibility only.
             */
            $id = $result;
            $got_string = false;
        }

        if (!is_resource($id)) {
            return $this->mysqlRaiseError(DB_ERROR_NEED_MORE_DATA);
        }

        if ($this->options['portability'] & DB_PORTABILITY_LOWERCASE) {
            $case_func = 'strtolower';
        } else {
            $case_func = 'strval';
        }

        $count = @mysql_num_fields($id);
        $res   = array();

        if ($mode) {
            $res['num_fields'] = $count;
        }

        for ($i = 0; $i < $count; $i++) {
            $res[$i] = array(
                'table' => $case_func(@mysql_field_table($id, $i)),
                'name'  => $case_func(@mysql_field_name($id, $i)),
                'type'  => @mysql_field_type($id, $i),
                'len'   => @mysql_field_len($id, $i),
                'flags' => @mysql_field_flags($id, $i),
            );
            if ($mode & DB_TABLEINFO_ORDER) {
                $res['order'][$res[$i]['name']] = $i;
            }
            if ($mode & DB_TABLEINFO_ORDERTABLE) {
                $res['ordertable'][$res[$i]['table']][$res[$i]['name']] = $i;
            }
        }

        // free the result only if we were called on a table
        if ($got_string) {
            @mysql_free_result($id);
        }
        return $res;
    }

    // }}}
    // {{{ getSpecialQuery()

    /**
     * Obtains the query string needed for listing a given type of objects
     *
     * @param string $type  the kind of objects you want to retrieve
     *
     * @return string  the SQL query string or null if the driver doesn't
     *                  support the object type requested
     *
     * @access protected
     * @see DB_common::getListOf()
     */
    function getSpecialQuery($type)
    {
        switch ($type) {
            case 'tables':
                return 'SHOW TABLES';
            case 'users':
                return 'SELECT DISTINCT User FROM mysql.user';
            case 'databases':
                return 'SHOW DATABASES';
            default:
                return null;
        }
    }

    // }}}

}

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