E faʻafefea ona vaʻai i le tulaga ma le faʻasologa o faʻamaumauga o faʻamaumauga o faʻamaumauga o faʻamatalaga o le MySQL database?

MySQL metadata

Atonu e te manaʻo e iloa vaega nei e tolu o faʻamatalaga e uiga i MySQL:

• Fa'amatalaga i'uga ole fesili: Ole numera o fa'amaumauga e a'afia ile SELECT, UPDATE po'o le DELETE fa'amatalaga.
• Fa'amatalaga fa'amaumauga ma laulau fa'amaumauga: O lo'o iai fa'amatalaga fa'atulagaina o fa'amaumauga ma laulau fa'amaumauga.
• MySQL fa'amatalaga server: O lo'o i ai le tulaga o lo'o iai nei, numera o fa'amatalaga, ma isi mea o le server database.

I le MySQL command prompt, e faigofie ona tatou mauaina faʻamatalaga o loʻo i luga. Ae afai e te faʻaaogaina se gagana tusitusi e pei ole Perl poʻo le PHP, e te manaʻomia le valaʻau i se galuega faʻaoga faʻapitoa e maua ai. O le a matou faʻalauiloa atili atu i le isi.

Maua le numera o fa'amaumauga e a'afia ile fa'amatalaga ole fesili

PERL fa'ata'ita'iga

I le DBI script, o le numera o faʻamaumauga e aʻafia i le faʻamatalaga e toe faʻafoʻi mai e ala i le galuega do () poʻo le faʻatinoina ():

# 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 fa'ata'ita'iga

I le PHP, e mafai ona e faʻaogaina le mysqli_affected_rows() galuega e maua ai le numera o faʻamaumauga e aʻafia i se faʻamatalaga fesili.

$result_id = mysqli_query ($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");

Lisi o fa'amaumauga ma laulau fa'amaumauga

E faigofie ona e mauaina se lisi o faʻamaumauga ma laulau ile MySQL server. Afai e le lava au fa'atagaga, o le fa'ai'uga o le a null.
E mafai fo'i ona e fa'aogaina le SHOW TABLES po'o le SHOW DATABASES fa'amatalaga e maua ai se lisi o fa'amaumauga ma laulau fa'amaumauga.

PERL fa'ata'ita'iga

# 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 fa'ata'ita'iga

O le faʻataʻitaʻiga o loʻo i lalo e faʻaalia uma faʻamaumauga i luga o le MySQL server:

<?
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);
?>

Maua metadata server

O faʻamatalaga faʻatonuga nei e mafai ona faʻaogaina i le MySQL command prompt poʻo totonu o tusitusiga, pei o PHP scripts.