Momwe mungasinthire funso mu database ya MySQL? UPDATE syntax/command/statement

Kodi mungatani kuti mufufuze UPDATE mu database ya MySQL ? UPDATE syntax/commands/statements.

MySQL UPDATE funso

Ngati tifunika kusintha kapena kusintha deta mu MySQL, tikhoza kugwiritsa ntchito lamulo la SQL UPDATE kuti tigwire ntchito. .

galamala

Zotsatirazi ndizomwe zili mu SQL syntax ya lamulo la UPDATE kuti musinthe deta ya MySQL data table:

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

• Mutha kusintha gawo limodzi kapena zingapo nthawi imodzi.
• Mutha kufotokoza chilichonse mu ndime ya KUTI.
• Mutha kusintha data nthawi imodzi patebulo limodzi.

The WHERE clause ndi yothandiza kwambiri pamene mukufunikira kusintha deta mumzere wotchulidwa pa tebulo la deta.

Sinthani data kudzera pa Command Prompt

Pansipa tidzagwiritsa ntchito ndime ya WHERE mu lamulo la SQL UPDATE kuti tisinthe zomwe zatchulidwa pa tebulo la chenweiliang_tbl:

Chitsanzo

Chitsanzo chotsatirachi chisintha mtengo wa chenweiliang_title field yomwe chenweiliang_id yake ndi 3 pa tebulo la data:

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)

Zotsatira zake, chenweiliang_title yomwe chenweiliang_id yake ndi 3 yasinthidwa.

Sinthani data pogwiritsa ntchito PHP script

PHP imagwiritsa ntchito mysqli_query() kuchita mawu a SQL. Mutha kugwiritsa ntchito kapena kusagwiritsa ntchito mawu akuti WHERE mu SQL UPDATE.

Dziwani: Musagwiritse ntchito gawo la WHERE kuti musinthe deta yonse yomwe ili patebulo, choncho samalani.

Ntchitoyi imakhala ndi zotsatira zofanana ndikuchita mawu a SQL mu mysql> command prompt.

Chitsanzo

Chitsanzo chotsatirachi chisintha zambiri za gawo la chenweiliang_title lomwe chenweiliang_id ndi 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);
?>