Pehea e ʻike ai i ke kūlana a me ka helu helu helu ʻikepili i ka ʻikepili o ka waihona MySQL?

MySQL metadata

Makemake paha ʻoe e ʻike i kēia mau ʻano ʻike ʻekolu e pili ana i MySQL:

• ʻIkepili hopena nīnau: Ka helu o nā moʻolelo i hoʻopili ʻia e ka ʻōlelo SELECT, UPDATE a i ʻole DELETE.
• ʻIke e pili ana i nā ʻikepili a me nā papa ʻikepili: Loaʻa ka ʻike kūkulu o ka waihona a me ka papa ʻikepili.
• ʻIke kikowaena MySQL: Loaʻa i ke kūlana o kēia manawa o ke kikowaena waihona, helu helu, etc.

Ma ke kauoha kauoha MySQL, hiki iā mākou ke loaʻa ka ʻike kikowaena ma luna.Akā inā hoʻohana ʻoe i kahi ʻōlelo kākau e like me Perl a i ʻole PHP, pono ʻoe e kāhea i kahi hana kikowaena kikoʻī e kiʻi ai.A laila e hoʻolauna mākou i nā kikoʻī.

E kiʻi i ka helu o nā moʻolelo i hoʻopili ʻia e ka ʻōlelo nīnau

laʻana PERL

Ma nā palapala DBI, ua hoʻihoʻi ʻia ka helu o nā moʻolelo i hoʻopili ʻia e ka ʻōlelo e nā hana do( ) a i ʻole execute( ):

# 方法 1
# 使用do( ) 执行  $query 
my $count = $dbh->do ($query);
# 如果发生错误会输出 0
printf "%d 条数据被影响\n", (defined ($count) ? $count : 0);
# 方法 2
# 使用prepare( ) 及 execute( ) 执行  $query 
my $sth = $dbh->prepare ($query);
my $count = $sth->execute ( );
printf "%d 条数据被影响\n", (defined ($count) ? $count : 0);

PHP laʻana

Ma PHP, hiki iā ʻoe ke hoʻohana i ka hana mysqli_affected_rows() e kiʻi i ka helu o nā moʻolelo i hoʻopili ʻia e kahi nīnau.

$result_id = mysqli_query ($conn_id, $query);
# 如果查询失败返回 
$count = ($result_id ? mysqli_affected_rows ($conn_id) : 0);
print ("$count 条数据被影响\n");

Ka papa inoa o nā waihona a me nā papa ʻikepili

Hiki iā ʻoe ke loaʻa kahi papa inoa o nā waihona a me nā papa ma ka server MySQL.Inā ʻaʻole lawa kāu ʻae, e hoʻihoʻi ka hopena i ka null.
Hiki iā ʻoe ke hoʻohana i ka ʻōlelo SHOW TABLES a i ʻole SHOW DATABASES e kiʻi i kahi papa inoa o nā waihona a me nā papa ʻikepili.

laʻana PERL

# 获取当前数据库中所有可用的表。
my @tables = $dbh->tables ( );
foreach $table (@tables ){
   print "表名 $table\n";
}

PHP laʻana

Hoʻopuka kēia hiʻohiʻona i nā ʻikepili āpau ma ka server MySQL:

<?
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
$db_list = mysqli_query($conn, 'SHOW DATABASES');
while ($db = mysqli_fetch_object($db_list))
{
 echo $db->Database . "<br />";
}
mysqli_close($conn);
?>

E kiʻi i ka metadata server

Hiki ke hoʻohana ʻia nā ʻōlelo kauoha aʻe ma ke kauoha kauoha MySQL a i ʻole ma nā palapala, e like me PHP scripts.