UWUHLAZIYA NJANI umbuzo kwisiseko sedatha seMySQL? HLAZIYA isivakalisi/umyalelo/ingxelo

MySQL databaseUHLAZIYA NJANI umbuzo? HLAZIYA isivakalisi/umyalelo/ingxelo

MySQL HLAZIYA umbuzo

Ukuba sifuna ukuguqula okanye ukuhlaziya idatha kwi-MySQL, sinokusebenzisa umyalelo we-SQL UPDATE wokusebenza. .

Igrama

Oku kulandelayo yisintaksi ye-SQL ngokubanzi yomyalelo we-UPDATE wokuguqula idatha yetafile yedatha ye-MySQL:

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

• Ungahlaziya indawo enye okanye ngaphezulu ngexesha elinye.
• Ungakhankanya nayiphi na imeko kwigatya apho.
• Unokuhlaziya idatha ngaxeshanye kwitafile enye.

Igatya elithi WHERE liluncedo kakhulu xa ufuna ukuhlaziya idatha kumqolo ochaziweyo kwitheyibhile yedatha.

Hlaziya idatha ngokusebenzisa umyalelo womyalelo

Ngezantsi siza kusebenzisa igatya elithi WHERE kumyalelo we-SQL UPDATE wokuhlaziya idatha ekhankanyiweyo kwitheyibhile ye-chenweiliang_tbl:

Umzekelo

Lo mzekelo ulandelayo uzakuhlaziya ixabiso lendawo ye-chenweiliang_title ene-chenweiliang_id isi-3 kwitheyibhile yedatha:

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)

Ukusuka kwisiphumo, i-chenweiliang_title ene-chenweiliang_id eyi-3 ilungisiwe.

Hlaziya idatha usebenzisa iscript sePHP

I-PHP isebenzisa umsebenzi mysqli_query() ukuphumeza iingxelo zeSQL.Ungasebenzisa okanye ungasebenzisi igatya elithi WHERE kwiingxelo zeSQL UPDATE.

Qaphela:Musa ukusebenzisa igatya elithi WHERE ukuhlaziya yonke idatha kwitheyibhile yedatha, ngoko lumka.

Lo msebenzi unesiphumo esifanayo sokwenza ingxelo yeSQL kwi-mysql> iprompt yomyalelo.

Umzekelo

Lo mzekelo ulandelayo uya kuhlaziya idatha ye-chenweiliang_title field leyo chenweiliang_id isi-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);
?>