MySQL daga amfani? share sanarwa a cikin bayanan MySQL

Yadda ake amfani da 'DELETE FROM' a cikin MySQL ? Menene kalmar 'DELETE' a cikin rumbun adana bayanai na MySQL ?

Bayanin MySQL DELETE

Kuna iya amfani da SQL DELETE DAGA umarni don share bayanan a cikin tebur na MySQL.

Za ka iya aiwatar da wannan umarni a cikin umarnin mysql> ko kuma rubutun PHP.

nahawu

Mai zuwa shine jigon bayanin SQL DELETE don share bayanai daga teburin bayanan MySQL:

DELETE FROM table_name [WHERE Clause]

• Idan babu INA da aka ƙayyade, za a share duk bayanan da ke cikin tebur na MySQL.
• Kuna iya ƙayyade kowane yanayi a cikin jumlar INA
• Kuna iya share bayanan gaba ɗaya a cikin tebur guda.

Maganar WHERE tana da amfani sosai lokacin da kake son share takamaiman bayanai a cikin tebur ɗin bayanai.

Share bayanai daga layin umarni

Anan zamu yi amfani da jumlar WHERE a cikin umarnin SQL DELETE don share bayanan da aka zaɓa daga teburin bayanan MySQL chenweiliang_tbl.

misali

Misali mai zuwa zai share rikodin tare da chenweiliang_id 3 a cikin tebur chenweiliang_tbl:

Share bayanai ta amfani da rubutun PHP

PHP yana amfani da aikin mysqli_query() don aiwatar da maganganun SQL, kuma zaku iya amfani da jumlar WHERE tare da ko ba tare da umarnin SQL DELETE ba.

Wannan aikin yana da tasiri iri ɗaya da aiwatar da umarnin SQL ta amfani da umarnin mysql> .

misali

Misalin PHP mai zuwa zai share rikodin tare da chenweiliang_id 3 a cikin tebur chenweiliang_tbl:

<?
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 = 'DELETE FROM chenweiliang_tbl
 WHERE chenweiliang_id=3';
 
mysqli_select_db( $conn, 'chenweiliang' );
$retval = mysqli_query( $conn, $sql );
if(! $retval )
{
 die('无法删除数据: ' . mysqli_error($conn));
}
echo '数据删除成功！';
mysqli_close($conn);
?>