PHP + MYSQL 座位预订系统。计算免费座位答案

【问题标题】：PHP + MYSQL Seating Reservation System. Counting free seatsPHP + MYSQL 座位预订系统。计算免费座位
【发布时间】：2013-03-01 08:20:21
【问题描述】：

我有一张这样的桌子：

    $sql = "CREATE TABLE dramaStudio
   (
   rowId varchar(1) not null,
   columnId int not null,
   status int,
   firstName varchar(15) not null,
   lastName varchar(15) not null,
   updatedby varchar(10),
   PRIMARY KEY (rowId, columnId)
   )";

在我的网站主页上，我希望用户能够查看是否有任何空闲座位，而无需进入座位计划。几乎只是说“免费座位：”后跟一个数字。我在伪代码中的逻辑是：

$j=0 
select * from dramaStudio
for every status == 0
    $j+1
echo $j

任何帮助将不胜感激。

【问题讨论】：

标签： php mysql for-loop select

【解决方案1】：

如果空位假设 status=0：

SELECT COUNT(*) AS freeseats FROM dramaStudio WHERE status=0

完整示例，来自 php 手册：

<?php
  $link = mysqli_connect("localhost", "my_user", "my_password", "world");

  /* check connection */
  if (mysqli_connect_errno()) {
      printf("Connect failed: %s\n", mysqli_connect_error());
      exit();
  }

  $query = "SELECT COUNT(*) AS freeseats FROM dramaStudio WHERE status=0";
  $result = mysqli_query($link, $query);

  /* associative array */
  $row = mysqli_fetch_array($result, MYSQLI_ASSOC);
  echo $row['freeseats']; // this is an integer

  /* free result set */
  mysqli_free_result($result);

  /* close connection */
  mysqli_close($link);
?>

【讨论】：

我将如何回应这个？回声计数？
仍然无法让这个回声，会是 AS $freeseats 吗？
?有任何想法吗。比较迷茫

【解决方案2】：

只需对所有状态为 0 的字段进行计数？

SELECT COUNT(*) FROM dramaStudio WHERE status = '0'

【讨论】：

LOL ... 为那些懒得将“FROM DramaStudio”放入 SQL 字符串的人更新。
知道答案就很容易了。

【解决方案3】：

查看示例代码

$con = mysql_connect("localhost", "peter", "abc123");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

$db_selected = mysql_select_db("test_db",$con);

$sql = "SELECT * from Person";
$result = mysql_query($sql,$con);

while ($property = mysql_fetch_field($result))
  {
  echo "Field name: " . $property->name . "<br />";
  echo "Table name: " . $property->table . "<br />";
  echo "Default value: " . $property->def . "<br />";
  echo "Max length: " . $property->max_length . "<br />";
  echo "Not NULL: " . $property->not_null . "<br />";
  echo "Primary Key: " . $property->primary_key . "<br />";
  echo "Unique Key: " . $property->unique_key . "<br />";
  echo "Mutliple Key: " . $property->multiple_key . "<br />";
  echo "Numeric Field: " . $property->numeric . "<br />";
  echo "BLOB: " . $property->blob . "<br />";
  echo "Field Type: " . $property->type . "<br />";
  echo "Unsigned: " . $property->unsigned . "<br />";
  echo "Zero-filled: " . $property->zerofill . "<br /><br />";
  }

mysql_close($con);

【讨论】：

【解决方案4】：

您要存放已坐满的座位吗？要找出空的，您必须指定列数和行数。

并且如果在表格中的状态可以区分已满座和空座。你可以这样做，

    $query = "select * from dramaStudio where status = 0";
    $result_Set = mysql_query($query);
    while($row = mysql_fetch_object($result_set)){
        echo $row->rowId .',', $row->columnId; 
        echo '</br>';
    }

【讨论】：