header("Content-type:application/vnd.ms-excel");

header("Content-Disposition:filename=54php.xls");

<?
/*
    [DreamCreation] (C)2007.
    This is NOT a freeware, use is subject to license terms

    #RCSfile:  index
    #Revision: 1.0  
    #Author:   Asen
    #Date:     2007/05/18 18:29:33
*/
$xlsname = date('ymdhis');
header("Content-type:application/vnd.ms-excel");
header("Content-Disposition:filename=$xlsname.xls"); //$xlsname　为随机文件名
?>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
    <tr>
        <td style="padding:25 10 10 10">
        <font color="#16387C"><strong>[경쟁사 투찰 성향]</strong></font>
        <table width="100%" border="0" cellspacing="0" cellpadding="0" >
            <tr>
                <td><font color="#16387C"><strong>총  건</strong></font></td>
                <td align="right">
                </td>
            </tr>
        </table>
        <table width="100%" border="1" cellpadding="5" cellspacing="1" bgcolor="#A3BCD2" style="margin-top:5px;">
            <tr>
                <td height="1" colspan="8"></td>
            </tr>
            <tr>
                <td height="1" colspan="8" align="right" bgcolor="#FFFFFF"></td>
            </tr>
            <tr align="center" bgcolor="#EEF3F6">
                <td width="5%" rowspan="2"><font color="#336699">No</font></td>
                <td width="35%"><font color="#336699">공고명</font></td>
                <td width="10%"><font color="#336699">입찰일자</font></td>
                <td width="10%"><font color="#336699">면허</font></td>
                <td width="10%"><font color="#336699">사정율</font></td>
                <td width="10%"><font color="#336699">투찰지점</font></td>
                <td width="10%"><font color="#336699">사정편차</font></td>
                <td width="10%" rowspan="2"><font color="#336699">순위</font></td>
            </tr>
            <tr align="center" bgcolor="#EEF3F6">
                <td><font color="#336699">발주처(실수요기관)</font></td>
                <td><font color="#336699">지역</font></td>
                <td><font color="#336699">기초금액</font></td>
                <td><font color="#336699">예정가격</font></td>
                <td><font color="#336699">투찰가격</font></td>
                <td><font color="#336699">기초대비율</font></td>
            </tr>
            <tr align="center" bgcolor="#FFFFFF">
                <td bgcolor="#EEF3F6" rowspan="2"> </td>
                <td> </td>
                <td> </td>
                <td> </td>
                <td> </td>
                <td> </td>
                <td> </td>
                <td rowspan="2"> </td>
            </tr>
            <tr align="center" bgcolor="#FFFFFF">
                <td> </td>
                <td> </td>
                <td> </td>
                <td> </td>
                <td> </td>
                <td> </td>
            </tr>
            <tr>
                <td height="1" colspan="8" align="right" bgcolor="#FFFFFF"></td>
            </tr>
            <tr>
                <td height="1" colspan="8"></td>
            </tr>
        </table>
        </td>
    </tr>
</table>

session_unregister,session_destroy和session_unset

session_unregister   是注销一个session变量;
session_destroy        是注销所有的session变量,并且结束session会话;
session_unset           并不注销session变量,但把所有的session变量的值清空

CHARSET(str) //返回字串字符集
CONCAT (string2  [,... ]) //连接字串
INSTR (string ,substring ) //返回substring首次在string中出现的位置,不存在返回0
LCASE (string2 ) //转换成小写
LEFT (string2 ,length ) //从string2中的左边起取length个字符
LENGTH (string ) //string长度
LOAD_FILE (file_name ) //从文件读取内容
LOCATE (substring , string  [,start_position ] ) 同INSTR,但可指定开始位置
LPAD (string2 ,length ,pad ) //重复用pad加在string开头,直到字串长度为length
LTRIM (string2 ) //去除前端空格
REPEAT (string2 ,count ) //重复count次
REPLACE (str ,search_str ,replace_str ) //在str中用replace_str替换search_str
RPAD (string2 ,length ,pad) //在str后用pad补充,直到长度为length
RTRIM (string2 ) //去除后端空格
STRCMP (string1 ,string2 ) //逐字符比较两字串大小,
SUBSTRING (str , position  [,length ]) //从str的position开始,取length个字符,
TRIM([[BOTH|LEADING|TRAILING] [padding] FROM]string2) //去除指定位置的指定字符
UCASE (string2 ) //转换成大写
RIGHT(string2,length) //取string2最后length个字符
SPACE(count) //生成count个空格