Otu esi emelite ajụjụ na MySQL nchekwa data? Melite syntax/iwu/ nkwupụta

Kedu otu esi eme ajụjụ UPDATE na nchekwa data MySQL ? UPDATE syntax/iwu/okwu.

MySQL Melite ajụjụ

Ọ bụrụ na anyị kwesịrị ịgbanwe ma ọ bụ melite data na MySQL, anyị nwere ike iji SQL UPDATE iwu iji rụọ ọrụ. .

ụtọ asụsụ

Ihe ndị a bụ syntax SQL izugbe maka iwu nkwalite iji gbanwee data tebụl data MySQL:

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

• Ị nwere ike imelite otu ubi ma ọ bụ karịa n'otu oge.
• Ị nwere ike ịkọwa ọnọdụ ọ bụla na nkebi ahịrịokwu WHERE.
• Ị nwere ike imelite data n'otu oge na otu tebụl.

Nkejiokwu WHERE bara ezigbo uru mgbe ịchọrọ imelite data n'ahịrị akọwapụtara na tebụl data.

Melite data site na ngwa ngwa

N'okpuru ebe a, anyị ga-eji ahịrịokwu WHERE dị na SQL UPDATE iwu iji melite data akọwapụtara na tebụl chenweiliang_tbl:

ihe atụ

Ihe atụ na-esonụ ga-emelite uru nke ubi chenweiliang_title nke chenweiliang_id bụ 3 na tebụl 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)

Site na nsonaazụ ya, agbanweela chenweiliang_title nke chenweiliang_id bụ 3.

Melite data site na iji script PHP

PHP na-eji mysqli_query() arụ ọrụ iji mebie nkwupụta SQL. Ị nwere ike iji ma ọ bụ ghara iji nkeji okwu WHERE dị na nkwupụta SQL UPDATE.

Rịba ama: Ejila nkeji WHERE melite data niile dị na tebụl ahụ, yabụ kpachara anya.

Ọrụ a nwere otu mmetụta dị ka imezu nkwupụta SQL na mysql> iwu ozugbo.

ihe atụ

Ihe atụ na-esonụ ga-emelite data nke ubi chenweiliang_title nke chenweiliang_id bụ 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);
?>