PHP MySQL Di mana
Klausa WHERE digunakan untuk menapis rekod, iaitu untuk menanyakan data mengikut syarat yang kami tentukan
Sintaksis
< table width=" -642">| 类型 | 详细解释 |
| 基本语法 | select 字段 from 表 where where条件; |
| 示例 | select * from money where age = 29; |
| 示例说明 | 查询MyGuests表中年龄为29的所有结果 |
Contoh berikut akan memilih semua Nama Pertama daripada jadual "MyGuests" =' Baris Mary:
<?php
header("Content-type:text/html;charset=utf-8"); //设置编码
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "test";
$con=mysqli_connect($servername, $username, $password, $dbname);
// 检测连接
if (mysqli_connect_errno())
{
echo "连接失败: " . mysqli_connect_error();
}
$result = mysqli_query($con,"SELECT * FROM MyGuests
WHERE FirstName='Mary'");
while($row = mysqli_fetch_array($result))
{
echo $row['firstname'] . "----" . $row['lastname'] ."----".$row['email'];
echo "<br>";
}
?>Hasil pelaksanaan program:
Gunakan keadaan di mana untuk menanyakan semua data FirstName='Mary' keluar.
Kami kini menggunakan phpadmin untuk menambah medan Umur pada jadual MyGuests
Data dalam jadual kini kelihatan seperti ini:
Contoh
Kami kini menggunakan klausa where untuk menanyakan mereka yang berumur kurang daripada 25:
<?php
header("Content-type:text/html;charset=utf-8"); //设置编码
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "test";
$con=mysqli_connect($servername, $username, $password, $dbname);
// 检测连接
if (mysqli_connect_errno())
{
echo "连接失败: " . mysqli_connect_error();
}
$result = mysqli_query($con,"SELECT * FROM MyGuests
WHERE Age<25 ");
while($row = mysqli_fetch_array($result))
{
echo $row['firstname'] . "----" . $row['lastname'] ."----".$row['email']."----".$row['Age'];
echo "<br>";
}
?>Keputusan berjalan program:
Anda juga boleh menggunakan syarat berikut
| <🎜> Penerangan<🎜><🎜> | ||||||||||
| > | Lebih besar daripada | ||||||||||
| < | > = | Lebih besar daripada atau sama dengan | |||||||||
| <= | Kurang daripada atau sama dengan |
| != | 不等于 |
| = | 等于 |
Pengendali logik
Simbol | Penerangan | ||||||
| atau | Atau | ||||||
| Dan |
<?php
header("Content-type:text/html;charset=utf-8"); //设置编码
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "test";
$con=mysqli_connect($servername, $username, $password, $dbname);
// 检测连接
if (mysqli_connect_errno())
{
echo "连接失败: " . mysqli_connect_error();
}
$result = mysqli_query($con,"SELECT * FROM MyGuests
WHERE Firstname='Julie' AND Age=24 ");
while($row = mysqli_fetch_array($result))
{
echo $row['firstname'] . "----" . $row['lastname'] ."----".$row['email']."----".$row['Age'];
echo "<br>";
}
?><🎜>Keputusan berjalan program: <🎜><🎜><🎜><🎜>bahagian seterusnya<?php
header("Content-type:text/html;charset=utf-8"); //设置编码
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "test";
$con=mysqli_connect($servername, $username, $password, $dbname);
// 检测连接
if (mysqli_connect_errno())
{
echo "连接失败: " . mysqli_connect_error();
}
$result = mysqli_query($con,"SELECT * FROM MyGuests
WHERE FirstName='Mary'");
while($row = mysqli_fetch_array($result))
{
echo $row['firstname'] . "----" . $row['lastname'] ."----".$row['email'];
echo "<br>";
}
?>
tiada