Question

我目前在MySQL数据库中有5个表。它们中的一些共享外键并且彼此相互依赖。我正在向他们的专业展示相应的课程。每个课程都在fall，spring或all_year期间授课。在我的数据库中，我有一个名为semester的表，其中包含id，year和semester字段。 semester字段特别是tinyint，其中包含三个值0，1，2。这表示fall，spring或all_year。当我显示查询而不是显示0或1或2时，我是否可以显示fall，spring等？额外：如何在每个循环的末尾添加空格，以便数据看起来不会聚集？

关键

0 Fall
1 Spring
2 All-year

PHP

<?


try {

    $pdo = new PDO ("mysql:host=$hostname;dbname=$dbname","$username","$pw");
    } catch (PDOException $e) {
    echo "Failed to get DB handle: " . $e->getMessage() . "\n";
    exit;
  }
      $query = $pdo->prepare("SELECT course.name, course.code, course.description, course.hours, semester.semester, semester.year
                            FROM course
                            LEFT JOIN major_course_xref ON course.id = major_course_xref.course_id
                            LEFT JOIN major ON major.id = major_course_xref.major_id
                            LEFT JOIN course_semester_xref ON course.id = course_semester_xref.course_id
                            LEFT JOIN semester ON course_semester_xref.semester_id = semester.id");
      $query->execute();

     if ($query->execute()){

      while ($row = $query->fetch(PDO::FETCH_ASSOC)){       
        print $row['name'] . "<br>";
        print $row['code'] . "<br>";
        print $row['description'] . "<br>";
        print $row['hours'] . " hrs.<br>";
        print $row['semester'] . "<br>";
        print $row['year'] . "<br>";
    }
    }
else
    echo 'Could not fetch results.';

      unset($pdo); 
      unset($query);

?>

当前显示

Computer Programming I
CPSC1400
Introduction to disciplined, object-oriented program development.
4 hrs.
0
2013

欲望展示

Computer Programming I
CPSC1400
Introduction to disciplined, object-oriented program development.
4 hrs.
Fall
2013

Answer 1

将查询中的semester.semester替换为：

CASE semester.semester
  WHEN 0 THEN 'Spring'
  WHEN 1 THEN 'Fall'
  WHEN 2 THEN 'All-year'
END semester

Answer 2

制作另一张桌子。说semester_time。

|  id  |  semester_time  |
|  0   |  Fall           |
|  1   |  Spring         |
|  2   |  All_year       |

然后在semester_time进行连接和后退。

基于上表的查询的可能模型：

SELECT course.name, course.code, course.description, course.hours, semester.semester, semester.year, semester_time 
                            FROM course
                            LEFT JOIN major_course_xref ON course.id = major_course_xref.course_id
                            LEFT JOIN major ON major.id = major_course_xref.major_id
                            LEFT JOIN course_semester_xref ON course.id = course_semester_xref.course_id
                            LEFT JOIN semester ON course_semester_xref.semester_id = semester.id
                            LEFT JOIN semester_time ON semester.semester = semester_time.id

在每个循环后添加空格

 while ($row = $query->fetch(PDO::FETCH_ASSOC)){       
        print $row['name'] . "<br>";
        print $row['code'] . "<br>";
        print $row['description'] . "<br>";
        print $row['hours'] . " hrs.<br>";
        print $row['semester'] . "<br>";
        print $row['year'] . "<br>";
        echo "<div class='add-space'></div>";
    }

在css中

.add-space {
margin-bottom: 15px; 
}

只需更改值即可满足您的需求。

Answer 3

while ($row = $query->fetch(PDO::FETCH_ASSOC)){       
        print $row['name'] . "<br>";
        print $row['code'] . "<br>";
        print $row['description'] . "<br>";
        print $row['hours'] . " hrs.<br>";
        print ($row['semester'] == 0) ? "FALL":( ($row['semester'] == 1) ? "Spring" : ( ($row['semester'] == 2) ? "All-year":"")) . "<br>";
        print $row['year'] . "<br>";
        print "<br>------------------------------<br />";
    }

使用php操作数据库表中的值

3 个答案: