我正在使用Perl的DBI。我知道$dbase->tables()
会返回相应数据库中的所有表。同样,我想知道数据库中可用的模式。是否有可用于此的函数?
你需要的是:DBI->table_info()
这样调用它:
my $sth = $dbh->table_info('', '%', '');
my $schemas = $dbh->selectcol_arrayref($sth, {Columns => [2]});
print "Schemas: ", join ', ', @$schemas;
这个有效。
创建一个数据库:
echo 'create table foo (bar integer primary key, quux varchar(30));' | sqlite3 foobar.sqlite
use 5.010;
use Data::Dumper qw(Dumper);
use DBIx::Class::Schema::Loader qw();
DBIx::Class::Schema::Loader->naming('current');
DBIx::Class::Schema::Loader->use_namespaces(1);
my $dbi_dsn = 'dbi:SQLite:dbname=foobar.sqlite';
my ($dbi_user, $dbi_pass);
my $schema = DBIx::Class::Schema::Loader->connect(
$dbi_dsn, $dbi_user, $dbi_pass, {'AutoCommit' => 1, 'RaiseError' => 1,}
);
for my $source_name ($schema->sources) {
say "*** Source: $source_name";
my $result_source = $schema->source($source_name);
for my $column_name ($result_source->columns) {
say "Column: $column_name";
say Dumper $result_source->column_info($column_name);
}
}
输出:
*** Source: Foo
Column: bar
$VAR1 = {
'data_type' => 'integer',
'is_auto_increment' => 1,
'is_nullable' => 1
};
Column: quux
$VAR1 = {
'data_type' => 'varchar',
'is_nullable' => 1,
'size' => 30
};
使用ODBC连接Oracle数据库时,我不得不使用这个变体来自于Uncle Arnie的答案:
my $table_info = $dbh->table_info(undef, '%', undef);
my $schemas = $table_info->fetchall_arrayref([1]);
print "Schemas :\n",
join( "\n", map {$_->[0]} @$schemas ), "\n";
selectcol_arrayref($sth, ...)
时,$schemas
将未定义。
DBI::ODBC
不支持table_info
,而我需要访问一个*.mdb
文件。 - reinierpost