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Mojo::Pg::Database(3) | User Contributed Perl Documentation | Mojo::Pg::Database(3) |
NAME¶
Mojo::Pg::Database - Database
SYNOPSIS¶
use Mojo::Pg::Database; my $db = Mojo::Pg::Database->new(pg => $pg, dbh => $dbh); $db->query('SELECT * FROM foo') ->hashes->map(sub { $_->{bar} })->join("\n")->say;
DESCRIPTION¶
Mojo::Pg::Database is a container for DBD::Pg database handles used by Mojo::Pg.
EVENTS¶
Mojo::Pg::Database inherits all events from Mojo::EventEmitter and can emit the following new ones.
close¶
$db->on(close => sub ($db) { ... });
Emitted when the database connection gets closed while waiting for notifications.
notification¶
$db->on(notification => sub ($db, $name, $pid, $payload) { ... });
Emitted when a notification has been received.
ATTRIBUTES¶
Mojo::Pg::Database implements the following attributes.
dbh¶
my $dbh = $db->dbh; $db = $db->dbh($dbh);
DBD::Pg database handle used for all queries.
# Use DBI utility methods my $quoted = $db->dbh->quote_identifier('foo.bar');
pg¶
my $pg = $db->pg; $db = $db->pg(Mojo::Pg->new);
Mojo::Pg object this database belongs to. Note that this attribute is weakened.
results_class¶
my $class = $db->results_class; $db = $db->results_class('MyApp::Results');
Class to be used by "query", defaults to Mojo::Pg::Results. Note that this class needs to have already been loaded before "query" is called.
METHODS¶
Mojo::Pg::Database inherits all methods from Mojo::EventEmitter and implements the following new ones.
begin¶
my $tx = $db->begin;
Begin transaction and return Mojo::Pg::Transaction object, which will automatically roll back the transaction unless "commit" in Mojo::Pg::Transaction has been called before it is destroyed.
# Insert rows in a transaction eval { my $tx = $db->begin; $db->insert('frameworks', {name => 'Catalyst'}); $db->insert('frameworks', {name => 'Mojolicious'}); $tx->commit; }; say $@ if $@;
delete¶
my $results = $db->delete($table, \%where, \%options);
Generate a "DELETE" statement with "abstract" in Mojo::Pg (usually an SQL::Abstract::Pg object) and execute it with "query". You can also append a callback to perform operations non-blocking.
$db->delete(some_table => sub ($db, $err, $results) { ... }); Mojo::IOLoop->start unless Mojo::IOLoop->is_running;
Use all the same argument variations you would pass to the "delete" method of SQL::Abstract.
# "DELETE FROM some_table" $db->delete('some_table'); # "DELETE FROM some_table WHERE foo = 'bar'" $db->delete('some_table', {foo => 'bar'}); # "DELETE from some_table WHERE foo LIKE '%test%'" $db->delete('some_table', {foo => {-like => '%test%'}}); # "DELETE FROM some_table WHERE foo = 'bar' RETURNING id" $db->delete('some_table', {foo => 'bar'}, {returning => 'id'});
delete_p¶
my $promise = $db->delete_p($table, \%where, \%options);
Same as "delete", but performs all operations non-blocking and returns a Mojo::Promise object instead of accepting a callback.
$db->delete_p('some_table')->then(sub ($results) { ... })->catch(sub ($err) { ... })->wait;
disconnect¶
$db->disconnect;
Disconnect "dbh" and prevent it from getting reused.
dollar_only¶
$db = $db->dollar_only;
Activate "pg_placeholder_dollaronly" for next "query" call and allow "?" to be used as an operator.
# Check for a key in a JSON document $db->dollar_only->query('SELECT * FROM foo WHERE bar ? $1', 'baz') ->expand->hashes->map(sub { $_->{bar}{baz} })->join("\n")->say;
insert¶
my $results = $db->insert($table, \@values || \%fieldvals, \%options);
Generate an "INSERT" statement with "abstract" in Mojo::Pg (usually an SQL::Abstract::Pg object) and execute it with "query". You can also append a callback to perform operations non-blocking.
$db->insert(some_table => {foo => 'bar'} => sub ($db, $err, $results) { ... }); Mojo::IOLoop->start unless Mojo::IOLoop->is_running;
Use all the same argument variations you would pass to the "insert" method of SQL::Abstract.
# "INSERT INTO some_table (foo, baz) VALUES ('bar', 'yada')" $db->insert('some_table', {foo => 'bar', baz => 'yada'}); # "INSERT INTO some_table (foo) VALUES ({1,2,3})" $db->insert('some_table', {foo => [1, 2, 3]}); # "INSERT INTO some_table (foo) VALUES ('bar') RETURNING id" $db->insert('some_table', {foo => 'bar'}, {returning => 'id'}); # "INSERT INTO some_table (foo) VALUES ('bar') RETURNING id, foo" $db->insert('some_table', {foo => 'bar'}, {returning => ['id', 'foo']});
As well as some PostgreSQL specific extensions added by SQL::Abstract::Pg.
# "INSERT INTO some_table (foo) VALUES ('{"test":23}')" $db->insert('some_table', {foo => {-json => {test => 23}}}); # "INSERT INTO some_table (foo) VALUES ('bar') ON CONFLICT DO NOTHING" $db->insert('some_table', {foo => 'bar'}, {on_conflict => undef});
Including operations commonly referred to as "upsert".
# "INSERT INTO t (a) VALUES ('b') ON CONFLICT (a) DO UPDATE SET a = 'c'" $db->insert('t', {a => 'b'}, {on_conflict => [a => {a => 'c'}]}); # "INSERT INTO t (a, b) VALUES ('c', 'd') ON CONFLICT (a, b) DO UPDATE SET a = 'e'" $db->insert('t', {a => 'c', b => 'd'}, {on_conflict => [['a', 'b'] => {a => 'e'}]});
insert_p¶
my $promise = $db->insert_p($table, \@values || \%fieldvals, \%options);
Same as "insert", but performs all operations non-blocking and returns a Mojo::Promise object instead of accepting a callback.
$db->insert_p(some_table => {foo => 'bar'})->then(sub ($results) { ... })->catch(sub ($err) { ... })->wait;
is_listening¶
my $bool = $db->is_listening;
Check if "dbh" is listening for notifications.
listen¶
$db = $db->listen('foo');
Subscribe to a channel and receive "notification" events when the Mojo::IOLoop event loop is running.
notify¶
$db = $db->notify('foo'); $db = $db->notify(foo => 'bar');
Notify a channel.
pid¶
my $pid = $db->pid;
Return the process id of the backend server process.
ping¶
my $bool = $db->ping;
Check database connection.
query¶
my $results = $db->query('SELECT * FROM foo'); my $results = $db->query('INSERT INTO foo VALUES (?, ?, ?)', @values); my $results = $db->query('SELECT ?::JSON AS foo', {-json => {bar => 'baz'}});
Execute a blocking SQL <http://www.postgresql.org/docs/current/static/sql.html> statement and return a results object based on "results_class" (which is usually Mojo::Pg::Results) with the query results. The DBD::Pg statement handle will be automatically reused when it is not active anymore, to increase the performance of future queries. You can also append a callback to perform operations non-blocking.
$db->query('INSERT INTO foo VALUES (?, ?, ?)' => @values => sub ($db, $err, $results) { ... }); Mojo::IOLoop->start unless Mojo::IOLoop->is_running;
Hash reference arguments containing a value named "-json" or "json" will be encoded to JSON text with "to_json" in Mojo::JSON. To accomplish the reverse, you can use the method "expand" in Mojo::Pg::Results, which automatically decodes all fields of the types "json" and "jsonb" with "from_json" in Mojo::JSON to Perl values.
# "I ♥ Mojolicious!" $db->query('SELECT ?::JSONB AS foo', {-json => {bar => 'I ♥ Mojolicious!'}}) ->expand->hash->{foo}{bar};
Hash reference arguments containing values named "type" and "value" can be used to bind specific DBD::Pg data types to placeholders.
# Insert binary data use DBD::Pg ':pg_types'; $db->query('INSERT INTO bar VALUES (?)', {type => PG_BYTEA, value => $bytes});
query_p¶
my $promise = $db->query_p('SELECT * FROM foo');
Same as "query", but performs all operations non-blocking and returns a Mojo::Promise object instead of accepting a callback.
$db->query_p('INSERT INTO foo VALUES (?, ?, ?)' => @values)->then(sub ($results) { ... })->catch(sub ($err) { ... })->wait;
select¶
my $results = $db->select($source, $fields, $where, \%options);
Generate a "SELECT" statement with "abstract" in Mojo::Pg (usually an SQL::Abstract::Pg object) and execute it with "query". You can also append a callback to perform operations non-blocking.
$db->select(some_table => ['foo'] => {bar => 'yada'} => sub ($db, $err, $results) { ... }); Mojo::IOLoop->start unless Mojo::IOLoop->is_running;
Use all the same argument variations you would pass to the "select" method of SQL::Abstract.
# "SELECT * FROM some_table" $db->select('some_table'); # "SELECT id, foo FROM some_table" $db->select('some_table', ['id', 'foo']); # "SELECT * FROM some_table WHERE foo = 'bar'" $db->select('some_table', undef, {foo => 'bar'}); # "SELECT * FROM some_table WHERE foo LIKE '%test%'" $db->select('some_table', undef, {foo => {-like => '%test%'}});
As well as some PostgreSQL specific extensions added by SQL::Abstract::Pg.
# "SELECT * FROM foo JOIN bar ON (bar.foo_id = foo.id)" $db->select(['foo', ['bar', foo_id => 'id']]); # "SELECT * FROM foo LEFT JOIN bar ON (bar.foo_id = foo.id)" $db->select(['foo', [-left => 'bar', foo_id => 'id']]); # "SELECT foo AS bar FROM some_table" $db->select('some_table', [[foo => 'bar']]); # "SELECT * FROM some_table WHERE foo = '[1,2,3]'" $db->select('some_table', '*', {foo => {'=' => {-json => [1, 2, 3]}}}); # "SELECT EXTRACT(EPOCH FROM foo) AS foo, bar FROM some_table" $db->select('some_table', [\'extract(epoch from foo) AS foo', 'bar']); # "SELECT 'test' AS foo, bar FROM some_table" $db->select('some_table', [\['? AS foo', 'test'], 'bar']);
Including a new last argument to pass many new options.
# "SELECT * FROM some_table WHERE foo = 'bar' ORDER BY id DESC" $db->select('some_table', '*', {foo => 'bar'}, {order_by => {-desc => 'id'}}); # "SELECT * FROM some_table LIMIT 10 OFFSET 20" $db->select('some_table', '*', undef, {limit => 10, offset => 20}); # "SELECT * FROM some_table WHERE foo = 23 GROUP BY foo, bar" $db->select('some_table', '*', {foo => 23}, {group_by => ['foo', 'bar']}); # "SELECT * FROM t WHERE a = 'b' GROUP BY c HAVING d = 'e'" $db->select('t', '*', {a => 'b'}, {group_by => ['c'], having => {d => 'e'}}); # "SELECT * FROM some_table WHERE id = 1 FOR UPDATE" $db->select('some_table', '*', {id => 1}, {for => 'update'}); # "SELECT * FROM some_table WHERE id = 1 FOR UPDATE SKIP LOCKED" $db->select('some_table', '*', {id => 1}, {for => \'update skip locked'});
select_p¶
my $promise = $db->select_p($source, $fields, $where, \%options);
Same as "select", but performs all operations non-blocking and returns a Mojo::Promise object instead of accepting a callback.
$db->select_p(some_table => ['foo'] => {bar => 'yada'})->then(sub ($results) { ... })->catch(sub ($err) { ... })->wait;
tables¶
my $tables = $db->tables;
Return table and view names for this database, that are visible to the current user and not internal, as an array reference.
# Names of all tables say for @{$db->tables};
unlisten¶
$db = $db->unlisten('foo'); $db = $db->unlisten('*');
Unsubscribe from a channel, "*" can be used to unsubscribe from all channels.
update¶
my $results = $db->update($table, \%fieldvals, \%where, \%options);
Generate an "UPDATE" statement with "abstract" in Mojo::Pg (usually an SQL::Abstract::Pg object) and execute it with "query". You can also append a callback to perform operations non-blocking.
$db->update(some_table => {foo => 'baz'} => {foo => 'bar'} => sub ($db, $err, $results) { ... }); Mojo::IOLoop->start unless Mojo::IOLoop->is_running;
Use all the same argument variations you would pass to the "update" method of SQL::Abstract.
# "UPDATE some_table SET foo = 'bar' WHERE id = 23" $db->update('some_table', {foo => 'bar'}, {id => 23}); # "UPDATE some_table SET foo = {1,2,3} WHERE id = 23" $db->update('some_table', {foo => [1, 2, 3]}, {id => 23}); # "UPDATE some_table SET foo = 'bar' WHERE foo LIKE '%test%'" $db->update('some_table', {foo => 'bar'}, {foo => {-like => '%test%'}}); # "UPDATE some_table SET foo = 'bar' WHERE id = 23 RETURNING id" $db->update('some_table', {foo => 'bar'}, {id => 23}, {returning => 'id'}); # "UPDATE some_table SET foo = '[1,2,3]' WHERE bar = 23" $db->update('some_table', {foo => {-json => [1, 2, 3]}}, {bar => 23});
update_p¶
my $promise = $db->update_p($table, \%fieldvals, \%where, \%options);
Same as "update", but performs all operations non-blocking and returns a Mojo::Promise object instead of accepting a callback.
$db->update_p(some_table => {foo => 'baz'} => {foo => 'bar'})->then(sub ($results) { ... })->catch(sub ($err) { ... })->wait;
SEE ALSO¶
Mojo::Pg, Mojolicious::Guides, <https://mojolicious.org>.
2022-03-16 | perl v5.40.0 |