如何使用php从另一个表中获取一个表字段值

我有一个数据库表cranedetails（字段是：

cf\u-did、cf\u-firstname、cf\u-cranetype

）

我有另一个表cranetype（

cf\u did，cf\u cname

）

我想显示这样的值， 例如：

等等

如何从表

cranetype

cf\u cranetype

中获取表cranedetails字段

cf\u cranetype

值（

2,3

）名称（崎岖不平的地面起重机、全地形起重机）

我是$did=1。然后使用这个代码

$sql=mysql_query("SELECT * FROM `cf_directory` WHERE `cf_did` = '$did'",$con);
$row = mysql_fetch_array($sql);$cn= $row['11']; 
$sql2=mysql_query("SELECT * FROM  `cf_cranetype`  WHERE `cf_ctid`= '$cn'",$con);
<?php  while($row2 = mysql_fetch_array($sql2)){
     $cranename=$row2['cf_ctname']; ?>
<?php echo $cranename;?>

我想：

id:    name:        cranetype

1      Alexy       ROUGH TERRAIN CRANES,ALL TERRAIN CRANES

---

使用子查询获取此文件以供参考

对于我来说，它看起来像是在存储由逗号连接的整数值（您的cranetype ID）组成的字符串值（或VARCHAR）

如果是这样的话，我会考虑重新设计你的数据库，如表，如
UL>

ChannEngas，CFJNID，CFI FieldNest

。

带有cf\u ctid cf\u ctname的cranetypes

带有cf\U did、cf\U nid、cf\U ctid的cranedetails

在cranedetails中，为与cranename关联的每个cranetype创建一个条目。当然，cf_nid和cf_ctid应该是与相应表的外键关系

在当前的设计中，必须分解cf_cranetype的字符串值以获得整数数组（或字符串，看起来像整数），第二个查询必须如下所示：

---

“从cf_ctid所在的cf_cranetype中选择*”。加入（$YOUR_数组，“，”）。“'”

您可以简单地使用

组CONCAT（）

和

在集合中查找（）

来实现：

SELECT
    cd.cf_did AS id,
    cd.cf_firstname AS name,
    GROUP_CONCAT(ct.cf_ctname SEPARATOR ', ') AS cranetype
FROM
    cranedetails cd,
    cranetype ct
WHERE
    FIND_IN_SET(ct.cf_ctid, cd.cf_cranetype)
GROUP BY
    cd.cf_did,
    cd.cf_firstname

输出为：

+----+----------+---------------------------------------------------------------------------------------+
| id | name     | cranetype                                                                             |
+----+----------+---------------------------------------------------------------------------------------+
|  1 | Alexy    | ROUGH TERRAIN CRANES, ALL TERRAIN CRANES                                              |
|  2 | Thomas   | ARICULATING BOOM CRANES, ELEVATORS, ALL TERRAIN CRANES                                |
|  3 | Thomas   | ALL TERRAIN CRANES, YARD CRANES, ARICULATING BOOM CRANES, ELEVATORS                   |
|  4 | Thomasxc | CRAWLER CRANES, ARICULATING BOOM CRANES, TRUCK CRANES: TELESCOPIC BOOM, MOBILE CRANES |
|  5 | Thomaseg | ALL TERRAIN CRANES, ELEVATORS, ELEVATOR – HYDRAULIC                                   |
+----+----------+---------------------------------------------------------------------------------------+
5 rows in set

如果只想按名称对结果进行分组（因为存在重复的名称），只需从查询中删除

cd.cf_did

，然后添加

DISTINCT

以过滤重复的

cranetype

值，即：

SELECT
    cd.cf_firstname AS name,
    GROUP_CONCAT(DISTINCT ct.cf_ctname SEPARATOR ', ') AS cranetype
FROM
    cranedetails cd,
    cranetype ct
WHERE
    FIND_IN_SET(ct.cf_ctid, cd.cf_cranetype)
GROUP BY
    cd.cf_firstname

结果将是：

+----------+---------------------------------------------------------------------------------------+
| name     | cranetype                                                                             |
+----------+---------------------------------------------------------------------------------------+
| Alexy    | ROUGH TERRAIN CRANES, ALL TERRAIN CRANES                                              |
| Thomas   | ELEVATORS, ALL TERRAIN CRANES, YARD CRANES, ARICULATING BOOM CRANES                   |
| Thomaseg | ELEVATORS, ELEVATOR – HYDRAULIC, ALL TERRAIN CRANES                                   |
| Thomasxc | TRUCK CRANES: TELESCOPIC BOOM, MOBILE CRANES, CRAWLER CRANES, ARICULATING BOOM CRANES |
+----------+---------------------------------------------------------------------------------------+
4 rows in set

---

你真的应该重新格式化问题和代码示例，使其更具可读性。

GROUP\u CONCAT（）

和

FIND\u IN\u SET（）

可以实现这个技巧，请参见下文。先生，这段代码“SELECT*FROM cf\u cranetype WHERE cf\u ctid IN”。加入（$YOUR_数组，“，”）。“'”无效。您是否重写了代码以获取所需的列并将其分解为数组（在我的示例中为$your_数组）？太好了！选择答案以关闭主题。好的..还有一个问题..如何检查此代码中的t条件选择cd.cf_firstname作为名称，选择GROUP_CONCAT（不同的ct.cf_ctname分隔符'，'）作为cranetype FROM cranedetails cd，cranetype ct WHERE FIND_in_SET（ct.cf_ctid，cd.cf_cranetype）按cd.cf_firstname分组我要检查cd.cf_payment='top'和cd.status='1'。我要检查cd.cf_payment='top'和cd.status='1'。我使用此代码选择cd.cf_did作为id，cd.cf_companyname作为名称，cd.cf_描述作为描述，cd.cf_payment作为付款，cd.cf_status作为状态，GROUP_CONCAT（ct.cf_ctname分隔符'，'））作为cf_目录cd中的cranetype，cf_cranetype ct WHERE cd.cf_payment='top'，cd.cf_status='1'，并按cd.cf_did，cd.cf_companyname，cd.cf_description，cd.cf_payment，cd.cf_status ORDER By cd.cf_did，cd.cf_cranetype按cd.cf_定义的组中的cranetype。但不起作用

SELECT
    cd.cf_did AS id,
    cd.cf_firstname AS name,
    GROUP_CONCAT(ct.cf_ctname SEPARATOR ', ') AS cranetype
FROM
    cranedetails cd,
    cranetype ct
WHERE
    FIND_IN_SET(ct.cf_ctid, cd.cf_cranetype)
GROUP BY
    cd.cf_did,
    cd.cf_firstname

+----+----------+---------------------------------------------------------------------------------------+
| id | name     | cranetype                                                                             |
+----+----------+---------------------------------------------------------------------------------------+
|  1 | Alexy    | ROUGH TERRAIN CRANES, ALL TERRAIN CRANES                                              |
|  2 | Thomas   | ARICULATING BOOM CRANES, ELEVATORS, ALL TERRAIN CRANES                                |
|  3 | Thomas   | ALL TERRAIN CRANES, YARD CRANES, ARICULATING BOOM CRANES, ELEVATORS                   |
|  4 | Thomasxc | CRAWLER CRANES, ARICULATING BOOM CRANES, TRUCK CRANES: TELESCOPIC BOOM, MOBILE CRANES |
|  5 | Thomaseg | ALL TERRAIN CRANES, ELEVATORS, ELEVATOR – HYDRAULIC                                   |
+----+----------+---------------------------------------------------------------------------------------+
5 rows in set

SELECT
    cd.cf_firstname AS name,
    GROUP_CONCAT(DISTINCT ct.cf_ctname SEPARATOR ', ') AS cranetype
FROM
    cranedetails cd,
    cranetype ct
WHERE
    FIND_IN_SET(ct.cf_ctid, cd.cf_cranetype)
GROUP BY
    cd.cf_firstname

+----------+---------------------------------------------------------------------------------------+
| name     | cranetype                                                                             |
+----------+---------------------------------------------------------------------------------------+
| Alexy    | ROUGH TERRAIN CRANES, ALL TERRAIN CRANES                                              |
| Thomas   | ELEVATORS, ALL TERRAIN CRANES, YARD CRANES, ARICULATING BOOM CRANES                   |
| Thomaseg | ELEVATORS, ELEVATOR – HYDRAULIC, ALL TERRAIN CRANES                                   |
| Thomasxc | TRUCK CRANES: TELESCOPIC BOOM, MOBILE CRANES, CRAWLER CRANES, ARICULATING BOOM CRANES |
+----------+---------------------------------------------------------------------------------------+
4 rows in set