Question

我在从2个表中检索一些数据然后将输出显示到一个区域时遇到问题。

这是我有的检索代码

$select_users = "SELECT CarID, Model, Year, Price, ManuName  FROM Vehicle, Manufacturer";
        //run query

        $result = mysql_query($select_users);

这是输出的代码

<?php
while ($user = mysql_fetch_array($result)){
$user_row = sprintf(
"<li><a href='select_veh.php?CarID=%d' class='mainnavstyle'>%s %s %s %s</a></li>", 
    $user['CarID'], 
    $user['ManuName'], 
    $user['Model'], 
    $user['Year'], 
    $user['Price']);
                echo $user_row;

           }
    ?>

我似乎无法获得“ManuName＆＃39;从另一张表中正确显示。目前使用此代码即可获得重复结果：

honda Civic 2000 $15,000

honda Corolla 1991 $5,000

Toyota Civic 2000 $15,000

Toyota Corolla 1991 $5,000

而不仅仅是

Honda Civic 2000 $15,000
Toyota Corolla 1991 $5,000

非常感谢任何帮助感谢

Answer 1

您正在执行交叉连接，该交叉连接与一个表的每一行匹配，与另一个表的每一行匹配。这几乎可以肯定是你不想要的。您需要限制表格的连接方式，为此，您的表格车辆和制造商需要彼此相关，如下：

CREATE TABLE manufacturer (
   id integer primary key auto_increment,
   name varchar(255)
  );

CREATE TABLE vehicle (
  id integer primary key auto_increment,
  name varchar(255),
  year integer,
  price double,
  manufacturer_id integer not null,
  FOREIGN KEY(manufacturer_id) REFERENCES manufacturer(id)
);

然后，您可以获得所需的信息：

SELECT m.name, v.name, v.year, v.price FROM vehicle v
    INNER JOIN manufacturer m
    ON v.manufacturer_id = m.id

您可以在此处查看此操作：http://sqlfiddle.com/#!9/5c1f2/1

Answer 2

在vehicle表格中我会得到制造商的外键，而不是查询：

SELECT Vehicle.CarID, Vehicle.Model, Vehicle.Year, Vehicle.Price, Vehicle.ManuName, Manufacturer.name INNER JOIN Manufacturer ON(Vehicle.manufacturerId = Manufacturer.id) FROM Vehicle

Answer 3

你可以使用联合或联接

一起进行SQL查询

或者，这也是你可以做的：

$sql1= "SELECT something FROM tbl WHERE column='".query."'";
$result1= $con->query($sql1);
if($result1->num_rows > 0){
    while($row = $result->fetch_assoc()) {     
        $rowans = $row["row"];

        $sql2= "SELECT * FROM tbl2 WHERE column2= '".something."'"; 
        $gettingRows2= $con->query($sql);
        if($gettingRows2->num_rows > 0){
            while($anotherrow= $sql2->fetch_assoc()) {
                $sql2Row= $anotherrow["row2"];
            }   
        }
    }
}
        echo $rowans." ".$sql2Row;

Php从2个表数据中添加mysql

3 个答案: