[請益] PHP+MYSQL問題

看板PHP作者ftseng (F)時間11年前 (2014/05/04 11:47)推噓0(0推 0噓 11→)

留言11則, 3人參與討論串1/1

請益各位高手大大，有3個相同的column的表格，但是內容不同。表格如下: a2 a4 a6 pid session a2a a2b pid session a4a a4b pid session a6a a6b ==================== ==================== ==================== 1 test 1 0 1 test 0 0 1 test 1 0 2 try 0 1 2 try 1 1 2 try 0 1 合併3個表格成為一個的程式如下: SELECT a2.session,a2.a2a,a2.a2b,a4.a4a,a4.a4b,a6.a6a,a6.a6b FROM a2 JOIN a4 ON a4.session = a2.session JOIN a6 ON a6.session = a4.session 得到的結果就是: session a2a a2b a4a a4b a6a a6b ================================ test 1 0 0 0 1 0 try 0 1 1 1 0 1 我想請益的問題，我想要做每個session的平均值該如何寫? session a2a a2b a4a a4b a6a a6b avg ==================================== test 1 0 0 0 1 0 ? try 0 1 1 1 0 1 ? 我寫的語法是: SELECT "a2.session,a2.a2a,a2.a2b,a4.a4a,a4.a4b,a6.a6a,a6.a6b AND AVG(a2.a2a+a2.a2b+a4.a4a+a4.a4b+a6.a6a+a6.a6b)/6 FROM a2 JOIN a4 ON a4.session = a2.session JOIN a6 ON a6.session = a4.session WHERE `session` LIKE '".$_SESSION["loginMember"]."'"; <table width="1200" border="1"> <tr> <td align='center'><div align="center">session</div></td> <td align='center'><div align="center">a2a</div></td> <td align='center'><div align="center">a2b</div></td> <td align='center'><div align="center">a4a</div></td> <td align='center'><div align="center">a4b</div></td> <td align='center'><div align="center">a6a</div></td> <td align='center'><div align="center">a6b</div></td> </tr> <?php $bgcolor = ""; $content = ""; mysql_data_seek($result, 0); while($record=mysql_fetch_array($result)){ echo "<tr>"; echo "<td>".$record['session']."</td>"; echo "<td>".$record['a2a']."</td>"; echo "<td>".$record['a2b']."</td>"; echo "<td>".$record['a4a']."</td>"; echo "<td>".$record['a4b']."</td>"; echo "<td>".$record['a6a']."</td>"; echo "<td>".$record['a6b']."</td>"; echo "</tr>"; } ?> </table> 請問如何讓黃色的avg出現? 謝謝各位大大幫忙 -- ※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 119.77.157.221 ※ 文章網址: http://www.ptt.cc/bbs/PHP/M.1399175222.A.A4D.html