Question

我需要通过连接从三个表中获取特定列。每次出错。我的代码是

    $saf=mysqli_query($db , "select pod.mobile, tpaidamount.Aptdate, follow.cent, pdate, time from pod,tpaidamount, follow where tpaidamount.pid = follow.pid and pod.Customer Id = tpaidamount.pid and pod.Customer Id =follow.pid ");
$i=1;

while($sfg=mysqli_fetch_assoc($saf) or die(mysqli_error($db)))
;
?>

pod,tpaidamount,follow are tables and other coloumns

获取错误您的SQL语法有错误;检查与您的MySQL服务器版本对应的手册，以便使用“Id = tpaidamount.pid”和“pod.Customer Id = follow.pid＆＃39;”附近的正确语法。在第1行

Answer 1

这是一个错字吗？是setfollowup.pid还是follow.pid？

select pod.mobile, tpaidamount.Aptdate, follow.cent, <table>.pdate, <table>.time
from pod, tpaidamount, follow
where tpaidamount.pid = follow.pid 
and pod.`Customer Id` = tpaidamount.pid 
and pod.`Customer Id` = follow.pid

Answer 2

您不应该创建带空格的列名。名称：＆＃34; pod.Customer Id＆＃34;是一个错误的属性名称，您需要避免使用数据类型（或任何SGBD保留字）之类的名称，如：＆＃39; date＆＃39;，＆＃39; time＆＃39;，＆＃39; char＆＃39; ，＆＃39;表＆＃39;，＆＃39;列＆＃39; .... 但是，如果您需要这样做，请尝试以下SQL：

SELECT p.mobile
, t.Aptdate
, f.cent
, ???.pdate
, ???.`time`
FROM pod AS p
JOIN tpaidamount AS t ON o.`Customer Id` = t.pid 
JOIN follow AS f ON t.pid = f.pid ON p.`Customer Id` = f.pid

使用别名可以轻松编写SQL查询。例如：table_name AS tn，table_a_name AS tan。
!!!我很高兴你看一些基本的SQL课程。祝你好运。

从三个表中获取特定列

2 个答案: