NAME
DBIx::Connection - Simple database interface.
SYNOPSIS
use DBIx::Connection;
my $connection = DBIx::Connection->new(
name => 'my_connection_name',
dsn => 'dbi:Oracle:localhost:1521/ORCL',
username => 'user',
password => 'password',
db_session_variables => {
NLS_DATE_FORMAT => 'DD.MM.YYYY'
}
);
or
my $dbh = DBI->connect(...);
my $connection = DBIx::Connection->new(
name => 'my_connection_name',
dbh => $dbh,
db_session_variables => {
NLS_DATE_FORMAT => 'DD.MM.YYYY'
}
);
my $cursor = $connection->query_cursor(sql => "select * from emp where deptno > ?", name => 'emp_select');
my $dataset = $cursor->execute([20]);
while ($cursor->fetch) {
#do some stuff ...
print $_ . " => " . $dataset->{$_}
for keys %$dataset;
}
{
my $cursor = $connection->find_query_cursor('emp_select');
my $dataset = $cursor->execute([20]);
...
}
my $record = $connection->record("select * from emp where empno = ?", 'xxx');
my $sql_handler = $connection->sql_handler(sql => "INSERT INTO emp(empno, ename) VALUES(?, ?)", name => 'emp_ins');
$sql_handler->execute(1, 'Smith');
$sql_handler->execute(2, 'Witek');
{
my $sql_handler= $connection->find_sql_handler('emp_ins');
$sql_handler->execute(3, 'Zzz');
...
}
#or
$connection->execute_statement("INSERT INTO emp(empno, ename) VALUES(?, ?)", 1, 'Smith');
#gets connection by name.
my $connection = DBIx::Connection->connection('my_connection_name');
do stuff
# returns connection to connection pool
$connection->close();
#turn on connection pooling
$DBIx::Connection::CONNECTION_POOLING = 1;
In this mode only connection may have the following states : in_use and NOT in_use,
Only connection that is "NOT in use" state can be retrieve by invoking DBIx::Connection->connection, and
state changes to "in use". Close method change state back to NOT in_use.
If in connection pool there are not connections in "NOT in use" state, then the new connection is cloned.
my $connection = DBIx::Connection->connection('my_connection_name');
# do stuff ...
$connection->close();
#preserving resource by physical disconnecting all connection that are idle by defined threshold (sec).
$DBIx::Connection::IDLE_THRESHOLD = 300;
DESCRIPTION
Represents a database connection handler.
It provides simple interface to managing database connections with the all related operations wrapped in the different sql handlers.
$connection = DBIx::Connection->connection('my_connection_name');
eval {
$connection->begin_work();
my $sql_handler = $connection->sql_handler(sql => "INSERT INTO emp(empno, ename) VALUES(?, ?)");
$sql_handler->execute(1, 'Smith');
...
$connection->commit();
};
if($@) {
$connection->rollback();
}
$connection->close();
It supports:
sql handlers(dml) -(INSERT/UDPDATE/DELETE)
my $sql_handler = $connection->sql_handler(sql => "INSERT INTO emp(empno, ename) VALUES(?, ?)");
$sql_handler->execute(1, 'Smith');
query cursors - SELECT ... FROM ...
my $query_cursor = $connection->query_cursor(
sql => "
SELECT t.* FROM (
SELECT 1 AS col1, 'text 1' AS col2 " . ($dialect eq 'oracle' ? ' FROM dual' : '') . "
UNION ALL
SELECT 2 AS col1, 'text 2' AS col2 " . ($dialect eq 'oracle' ? ' FROM dual' : '') . "
) t
WHERE 1 = ? "
);
my $resultset = $cursor->execute([1]);
while($cursor->fetch()) {
# do some stuff
# $resultset
}
plsql handlers - BEGIN ... END
my $plsql_handler = $connection->plsql_handler(
name => 'test_block',
plsql => "BEGIN
:var1 := :var2 + :var3;
END;",
bind_variables => {
var1 => {type => 'SQL_INTEGER'},
var2 => {type => 'SQL_INTEGER'},
var3 => {type => 'SQL_INTEGER'}
}
);
my $resultset = $plsql_handler->execute(var2 => 12, var3 => 8);
Connection is cached by its name.
DBIx::Connection->new(
name => 'my_connection_name',
dsn => 'dbi:Oracle:localhost:1521/ORCL',
username => 'user',
password => 'password',
);
$connection = DBIx::Connection->connection('my_connection_name');
RDBMS session variables supports.
my $databaseHandler = DBIx::Connection->new(
name => 'my_connection_name',
dsn => 'dbi:Oracle:localhost:1521/ORCL',
username => 'user',
password => 'password',
db_session_variables => {
NLS_DATE_FORMAT => 'DD.MM.YYYY'
}
)
It caches sql statements based on handler's name.
$connection->sql_handler(name => 'emp_ins', sql => "INSERT INTO emp(empno, ename) VALUES(?, ?)");
my $sql_handler = $connection->find_sql_handler('emp_ins');
$sql_handler->execute(1, 'Smith');
Database usage:
This module allows gathering sql statistics issued by application
Automatic reporting:
$connection->set_collect_statistics(1);
$connection->set_statistics_dir('/sql_usage');
Error handler customization:
It supports error handler customization.
my $error_handler = sub {
my (self, $message, $sql_handler) = @_;
#do some stuff
};
$connection->set_custom_error_handler($error_handler);
Sequences support:
$connection->sequence_value('emp_seq');
Large Object support;
$connection->update_lob(lob_test => 'blob_content', $lob_content, {id => 1}, 'doc_size');
my $lob = $connection->fetch_lob(lob_test => 'blob_content', {id => 1}, 'doc_size');
ATTRIBUTES
- name
-
Connection name.
- dsn
-
Database source name.
- username
- password
- database handler
- db_session_variables
- query_cursors
- sql_handlers
- plsql_handlers
- custom_error_handler
-
Callback that overwrites default error_handler on SQLHandler object.
- stats
- action_start_time
- collect_statistics
-
Flag that indicate if statistics are collected.
- statistics_dir
- in_use
- is_connected
- last_in_use
- no_cache
-
Prepares statements each time, otherwise use prepare statement once and reuse it
- _active_transaction
-
Flag that indicate that connection has pending transaction
METHODS
- load_module
-
Loads specific rdbms module.
- connect
-
Connects to the database.
- check_connection
-
Checks the database connection and reconnects if necessary.
- do
-
Executes passed in sql statement.
- sql_handler
-
Returns a new sql handler instance.
my $sql_handler = $connection->sql_handler( name => 'emp_ins' sql => "INSERT INTO emp(empno, ename) VALUES(?, ?)", ); $sql_handler->execute(1, 'Smith');
- find_sql_handler
-
Returns cached sql handler. Takes sql handler name as parameter.
my $sql_handler = $connection->find_sql_handler('emp_ins'); $sql_handler->execute(1, 'Scott');
- execute_statement
-
Executes passed in statement.
$connection->execute_statement("INSERT INTO emp(empno, ename) VALUES(?, ?)", 1, 'Smith');
- query_cursor
-
my $cursor = $connection->query_cursor(sql => "SELECT * FROM emp WHERE empno = ?"); my @result_set; $cursor->execute([1], \@result_set); or # my $result_set = $cursor->execute([1]); my $iterator = $cursor->iterator; while($iterator->()) { #do some stuff #@result_set } # or while($cusor->fetch()) { #do some stuff #@result_set }
- find_query_cursor
-
Returns cached query cursor. Takes query cursor name as parameter.
my $cursor = $connection->find_query_cursor('my_cusror'); my $result_set = $cursor->execute([1]);
- plsql_handler
-
Returns a new plsql handler instance <DBIx::PLSQLHandler>. Takes DBIx::PLSQLHandler constructor parameters.
my $plsql_handler = $connection->plsql_handler( name => 'my_plsql', plsql => "DECLARE debit_amt CONSTANT NUMBER(5,2) := 500.00; BEGIN SELECT a.bal INTO :acct_balance FROM accounts a WHERE a.account_id = :acct AND a.debit > debit_amt; :extra_info := 'debit_amt: ' || debit_amt; END;"); my $result_set = $plsql_handler->execute(acct => 000212); print $result_set->{acct_balance}; print $result_set->{extra_info};
- find_plsql_handler
-
Returns cached plsql handler, takes name of handler.
my $plsql_handler = $connection->find_plsql_handler('my_plsql'); my $result_set = $plsql_handler->execute(acct => 000212);
- record
-
Returns resultset record. Takes sql statement, and bind variables parameters as list.
my $resultset = $connection->record("SELECT * FROM emp WHERE ename = ? AND deptno = ? ", 'scott', 10); #$resultset->{ename} # do some stuff
- begin_work
-
Begins transaction.
- commit
-
Commits current transaction.
- rollback
-
Rollbacks current transaction.
- initialise
-
Initializes connection.
- connection
-
Returns connection object for passed in connection name.
- has_autocomit_mode
-
Returns true if connection has autocommit mode
- _find_connection
-
Finds connections
- _cache_connection
-
Checks connection
- _clone_connection
-
Clones current connection. Returns a new connection object.
- _check_connection
-
Checks connection state.
- _is_idled
-
returns true if connection is idle.
- check_connnections
-
Checks all connection and disconnects all inactive for longer the 5 mins
- close
-
Returns connection to the connection pool, so that connection may be reused by another call Connection->connection('connection_name') rather then its clone.
- disconnect
-
Disconnects from current database.
- dbms_name
-
Returns database name
- dbms_version
-
Returns database version
- primary_key_info
-
Returns primary key information, takes table name Return array ref (DBI::primary_key_info)
my $pk_info = $connection->primary_key_info($table); my $pk_info = $connection->primary_key_info($table, $schema);
- primary_key_columns
-
Returns primary key columns
my @primary_key_columns = $connection->primary_key_columns('emp');
- foreign_key_info
-
Return foreign key info.
my $fk_info = $connection->primary_key_info($table, $ref_table); my $fk_info = $connection->primary_key_info($table, $ref_table, $schema, $ref_schema);
- foreign_key_columns
-
Returns foreign key columns
my @columns = $connection->foreign_key_columns($table, $ref_table); my @columns = $connection->foreign_key_columns($table, $ref_table, $schema, $ref_schema);
- index_info
-
Returns index data structure for the specified index.
my $index_info = $connection->index_info($index); my $index_info = $connection->index_info($index, $schema); my $index_info = $connection->index_info($index, $schema, $table);
- table_info
-
Returns table info. See also DBI::table_info
my $table_info = $db_connection->table_info($table); my $table_info = $db_connection->table_info($table, $schema);
- trigger_info
-
Returns trigger info.
my $trigger_info = $connection->trigger_info($trigger); my $trigger_info = $connection->trigger_info($trigger, $schema);
Result hash ref has the following keys
trigger_name table_name trigger_schema description trigger_body
- routine_info
-
Returns array ref of the following hash ref structure:
'return_type' => 'routine_schema' => 'routine_name' => 'routine_arguments' => 'routine_body' => 'routine_type' => 'FUNCTION|PROCEDURE' 'args' => [ { mode => ...., name => ..., type => ... }, ... ], my $routines_info = $connection->routine_info($function, $schema); my $routines_info = $connection->routine_info($function);
Takes procedure/function name as parameter.
- set_session_variables
- has_table
-
Returns true if the specified table exists
$connection->has_table($table, $schema); $connection->has_table($table);
- has_view
-
Returns true if the specified view exists
$connection->has_table($table, $schema); $connection->has_table($table);
- has_sequence
-
Returns true if has sequence
- sequence_value
-
Returns sequence's value. Takes sequence name.
$connection->sequence_value('emp_seq');
- reset_sequence
-
Restart sequence. Takes sequence name, initial sequence value, incremental sequence value.
$connection->reset_sequence('emp_seq', 1, 1);
- tables_info
-
Returns list of schema tables; Takes optionally schema name.
- columns
-
Returns columns for passed in table.
$connection->columns($table); $connection->columns($table, $schema);
- column
-
Returns the hash ref to column info for given table.
$connection->column($table, $column); $connection->column($table, $column, $schema);
- record_action_start_time
-
Records database operation start time.
- record_action_end_time
-
Records database operation end time.
- format_usage_report
-
Formats usage report.
- print_usage_report
-
Prints usage report to stander output.
- print_usage_report_to_file
-
Prints usage report to file
- error_handler
-
Returns error message, takes error message, and optionally bind variables. If bind variables are passed in the sql's place holders are replaced with the bind_variables.
- update_lob
-
Updates lob.
Takes table_name, lob column name, lob content, hash_ref to primary key values. optionally lob size column name.
$connection->update_lob(lob_test => 'blob_content', $lob_content, {id => 1}, 'doc_size');
- fetch_lob
-
Returns lob, takes table name, lob column name, hash ref of primary key values, lob size column name
my $lob = $connection->fetch_lob(lob_test => 'blob_content', {id => 1}, 'doc_size');
- _where_clause
-
Returns Where clause sql fragment, takes hash ref of fields values.
- DESTORY
COPYRIGHT AND LICENSE
The DBIx::Connection module is free software. You may distribute under the terms of either the GNU General Public License or the Artistic License, as specified in the Perl README file.
SEE ALSO
DBIx::QueryCursor DBIx::SQLHandler DBIx::PLSQLHandler.
AUTHOR
Adrian Witas, adrian@webapp.strefa.pl