Mojo::Pg::Database - Database

NAME SYNOPSIS DESCRIPTION EVENTS close notification ATTRIBUTES dbh pg results_class METHODS begin delete delete_p disconnect dollar_only insert insert_p is_listening listen notify pid ping query query_p select select_p tables unlisten update update_p SEE ALSO

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 â¥ Mojolicious!"
$db−>query('SELECT ?::JSONB AS foo', {−json => {bar => 'I â¥ 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;