NAME
DB::Object::Postgres::Tables - PostgreSQL Table Object
SYNOPSIS
use DB::Object::Postgres::Tables;
my $this = DB::Object::Postgres::Tables->new ||
die( DB::Object::Postgres::Tables->error, "\n" );
VERSION
v0.5.1
DESCRIPTION
This is a PostgreSQL table object class. It inherits from DB::Object::Tables
METHODS
create
This creates a table.
It takes some array reference data containing the columns definitions, some optional parameters and a statement handler.
If a statement handler is provided, then no need to provide an array reference of columns definition. The columns definition will be taken from the statement handler. However, at least either one of them needs to be provided to set the columns definition.
Possible parameters are:
- comment
- inherits
-
Takes the name of another table to inherit from
- on commit
- tablespace
- temporary
-
If provided, this will create a temporary table.
- with oids
-
If true, this will enable table oid
- without oids
-
If true, this will disable table oid
This will return an error if the table already exists, so best to check beforehand with "exists".
Upon success, it will return the new statement to create the table. However, if "create" is called in void context, then the statement is executed right away and returned.
create_info
This returns the create info for the current table object as a string representing the sql script necessary to recreate the table.
disable_trigger
my $sth = $tbl->disable_trigger;
my $sth = $tbl->disable_trigger( all => 1 );
my $sth = $tbl->disable_trigger( name => 'my_trigger' );
Provided with some optional parameters and this will return a statement handler to disable all triggers or a given trigger on the table.
If it is called in void context, then the statement is executed immediately and returned, otherwise it is just returned.
$tbl->disable_trigger;
# would issue immediately the following query:
ALTER TABLE my_table DISABLE TRIGGER USER
It takes the following options:
- all
-
If true, this will disable all trigger on the table. Please note that, as per the PostgreSQL documentation this requires super user privilege.
If false, this will disable only the user triggers, i.e. not including the system ones.
- name
-
If a trigger name is provided, it will be used to specifically disable this trigger.
drop
This will prepare a drop statement to drop the current table.
If it is called in void context, then the statement is executed immediately and returned, otherwise it is just returned.
It takes the following options:
- cascade
-
If true,
CASCADE
will be added to theDROP
query. - if_exists
-
If true, this will add a
IF EXISTS
to theDROP
query.You can also use if-exists
- restrict
-
If true,
RESTRICT
will be added to theDROP
query.
See PostgreSQL documentation for more information
enable_trigger
my $sth = $tbl->enable_trigger;
my $sth = $tbl->enable_trigger( all => 1 );
my $sth = $tbl->enable_trigger( name => 'my_trigger' );
Provided with some optional parameters and this will return a statement handler to enable all triggers or a given trigger on the table.
If it is called in void context, then the statement is executed immediately and returned, otherwise it is just returned.
$tbl->enable_trigger;
# would issue immediately the following query:
ALTER TABLE my_table ENABLE TRIGGER USER
It takes the following options:
- all
-
If true, this will enable all trigger on the table. Please note that, as per the PostgreSQL documentation this requires super user privilege.
If false, this will enable only the user triggers, i.e. not including the system ones.
- name
-
If a trigger name is provided, it will be used to specifically enable this trigger.
exists
Returns true if the current table exists, or false otherwise.
lock
This will prepare a query to lock the table and return the statement handler. If it is called in void context, the statement handler returned is executed immediately.
It takes an optional lock type and an optional NOWAIT
parameter.
Supported lock types are:
ACCESS SHARE
ROW SHARE
ROW EXCLUSIVE
SHARE UPDATE EXCLUSIVE
SHARE
SHARE ROW EXCLUSIVE
EXCLUSIVE
ACCESS EXCLUSIVE
See PostgreSQL documentation for more information
on_conflict
A convenient wrapper to "on_conflict" in DB::Object::Postgres::Query
optimize
Not implemented in PostgreSQL.
qualified_name
This return a fully qualified name to be used as a prefix to columns in queries.
If "prefixed" in DB::Object::Tables is greater than 2, the database name will be added.
If there is a schema defined and the "prefixed" in DB::Object::Tables is greater than 1, the schema will be added.
At minimum, the table name is added.
$tbl->prefixed(2);
$tbl->qualified_name;
# Would return something like: mydb.my_schema.my_table
$tbl->prefixed(1);
$tbl->qualified_name;
# Would return only: my_table
rename
Provided with a new table name, and this will prepare the necessary query to rename the table and return the statement handler.
If it is called in void context, the statement handler is executed immediately.
# Get the prefs table object
my $tbl = $dbh->pref;
$tbl->rename( 'prefs' );
# Would issue a statement handler for the query: ALTER TABLE pref RENAME TO prefs
See PostgreSQL documentation for more information
repair
Not implemented in PostgreSQL.
stat
Not implemented in PostgreSQL.
structure
This returns, in list context, an hash and, in scalar context, an hash reference of the table structure.
The hash, or hash reference returned contains the column name and its definition.
The data returned is cached, so it fetches the information from PostgreSQL only once.
This method will also set the following object properties:
- "type" in DB::Object::Tables
-
The table type.
- "schema" in DB::Object::Tables
-
The table schema.
- default
-
A column name to default value hash reference
- fields
-
A column name to field position (integer) hash reference
- null
-
A column name to a boolean representing whether the column is nullable or not.
- "primary" in DB::Object::Tables
-
An array reference of column names that are used as primary key for the table.
- structure
-
A column name to its sql definition
- types
-
A column name to column data type hash reference
unlock
This will unlock a previously locked table.
If an argument is provided, this calls instead CORE::unlock
passing it whatever parameters provided.
Otherwise, it will prepare a query UNLOCK TABLES
and returns the statement handler.
If it is called in void context, this will execute the statement handler immediately.
SEE ALSO
AUTHOR
Jacques Deguest <jack@deguest.jp>
COPYRIGHT & LICENSE
Copyright (c) 2019-2021 DEGUEST Pte. Ltd.
You can use, copy, modify and redistribute this package and associated files under the same terms as Perl itself.