UNGABUYEKEZA kanjani umbuzo ku-database ye-MySQL? BUYEKEZA i-syntax/umyalo/isitatimende

Ungawenza kanjani umbuzo we-UPDATE kusizindalwazi se-MySQL ? UPDATE syntax/commands/statements.

MySQL BUYEKEZA umbuzo

Uma sidinga ukulungisa noma ukubuyekeza idatha ku-MySQL, singasebenzisa umyalo we-SQL UPDATE ukuze sisebenze. .

uhlelo lolimi

Okulandelayo i-syntax ye-SQL evamile yomyalo WE-UPDATE wokushintsha idatha yetafula ledatha ye-MySQL:

UPDATE table_name SET field1=new-value1, field2=new-value2
[WHERE Clause]

• Ungabuyekeza inkambu eyodwa noma ngaphezulu ngesikhathi esisodwa.
• Ungacacisa noma yimuphi umbandela esigatshaneni esithi LAPHO.
• Ungabuyekeza idatha ngesikhathi esisodwa kuthebula elilodwa.

Isigatshana esithi LAPHO siwusizo kakhulu uma udinga ukubuyekeza idatha kumugqa oshiwo kuthebula ledatha.

Buyekeza idatha ngomyalo womyalo

Ngezansi sizosebenzisa isigatshana esithi WHERE kumyalo we-SQL UPDATE ukuze sibuyekeze idatha eshiwo kuthebula le-chenweiliang_tbl:

Isibonelo

Isibonelo esilandelayo sizobuyekeza inani lenkambu ye-chenweiliang_title lapho i-chenweiliang_id yayo ingu-3 kuthebula ledatha:

mysql> UPDATE chenweiliang_tbl SET chenweiliang_title='学习 C++' WHERE chenweiliang_id=3;
Query OK, 1 rows affected (0.01 sec)
 
mysql> SELECT * from chenweiliang_tbl WHERE chenweiliang_id=3;
+-----------+--------------+---------------+-----------------+
| chenweiliang_id | chenweiliang_title | chenweiliang_author | submission_date |
+-----------+--------------+---------------+-----------------+
| 3 | 学习 C++ | chenweiliang.com | 2016-05-06 |
+-----------+--------------+---------------+-----------------+
1 rows in set (0.01 sec)

Kusukela kumphumela, i-chenweiliang_title i-chenweiliang_id yayo engu-3 ishintshiwe.

Buyekeza idatha usebenzisa umbhalo we-PHP

I-PHP isebenzisa umsebenzi othi mysqli_query() ukuze isebenzise izitatimende ze-SQL. Ungasebenzisa noma ungasebenzisi isigatshana esithi LAPHO ezitatimendeni ze-SQL UPDATE.

Qaphela: Ungasebenzisi isigatshana esithi WHERE ukuze ubuyekeze yonke idatha etafuleni, ngakho-ke qaphela.

Lo msebenzi unomphumela ofanayo nokwenza isitatimende se-SQL ku-mysql> umyalo womyalo.

Isibonelo

Isibonelo esilandelayo sizobuyekeza idatha yenkambu ye-chenweiliang_title okuthi chenweiliang_id yayo ingu-3.

<?
php
$dbhost = 'localhost:3306'; // mysql服务器主机地址
$dbuser = 'root'; // mysql用户名
$dbpass = '123456'; // mysql用户名密码
$conn = mysqli_connect($dbhost, $dbuser, $dbpass);
if(! $conn )
{
 die('连接失败: ' . mysqli_error($conn));
}
// 设置编码，防止中文乱码
mysqli_query($conn , "set names utf8");
 
$sql = 'UPDATE chenweiliang_tbl
 SET chenweiliang_title="学习 Python"
 WHERE chenweiliang_id=3';
 
mysqli_select_db( $conn, 'chenweiliang' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
 die('无法更新数据: ' . mysqli_error($conn));
}
echo '数据更新成功！';
mysqli_close($conn);
?>