# Copyright (c) 1999-2017 H.Merijn Brand
#
# You may distribute under the terms of either the GNU General Public
# License or the Artistic License, as specified in the Perl README file.
use 5.8.4;
use strict;
use warnings;
package DBD::Unify;
our $VERSION = "0.88";
=head1 NAME
DBD::Unify - DBI driver for Unify database systems
=head1 SYNOPSIS
# Examples marked NYT are Not Yet Tested, they might work
# all others have been tested.
# man DBI for explanation of each method (there's more than listed here)
$dbh = DBI->connect ("DBI:Unify:[\$dbname]", "", $schema, {
AutoCommit => 0,
ChopBlanks => 1,
uni_unicode => 0,
uni_verbose => 0,
uni_scanlevel => 2,
});
$dbh = DBI->connect_cached (...); # NYT
$dbh->do ($statement);
$dbh->do ($statement, \%attr);
$dbh->do ($statement, \%attr, @bind);
$dbh->commit;
$dbh->rollback;
$dbh->disconnect;
$all = $dbh->selectall_arrayref ($statement);
@row = $dbh->selectrow_array ($statement);
$col = $dbh->selectcol_arrayref ($statement);
$sth = $dbh->prepare ($statement);
$sth = $dbh->prepare ($statement, \%attr);
$sth = $dbh->prepare_cached ($statement); # NYT
$sth->execute;
@row = $sth->fetchrow_array;
$row = $sth->fetchrow_arrayref;
$row = $sth->fetchrow_hashref;
$all = $sth->fetchall_arrayref;
$sth->finish;
# Statement has placeholders like where field = ?
$sth = $dbh->prepare ($statement);
$sth->bind_param ($p_num, $bind_value); # NYT
$sth->bind_param ($p_num, $bind_value, $bind_type); # NYT
$sth->bind_param ($p_num, $bind_value, \%attr); # NYT
$sth->bind_col ($col_num, \$col_variable); # NYT
$sth->bind_columns (@list_of_refs_to_vars_to_bind);
$sth->execute (@bind_values);
$cnt = $sth->rows;
$sql = $dbh->quote ($string);
$err = $dbh->err;
$err = $sth->err;
$str = $dbh->errstr;
$str = $sth->errstr;
$stt = $dbh->state;
$stt = $sth->state;
For large DB fetches the combination $sth->bind_columns ()
with $sth->fetchrow_arrayref is the fastest (DBI
documentation).
=cut
# The POD text continues at the end of the file.
###############################################################################
use Carp;
use DBI 1.42;
use DynaLoader ();
use vars qw(@ISA);
@ISA = qw(DynaLoader);
bootstrap DBD::Unify $VERSION;
our $err = 0; # holds error code for DBI::err
our $errstr = ""; # holds error string for DBI::errstr
our $state = ""; # holds SQL state for DBI::state
our $drh = undef; # holds driver handle once initialized
sub driver {
return $drh if $drh;
my ($class, $attr) = @_;
$class .= "::dr";
# not a 'my' since we use it above to prevent multiple drivers
$drh = DBI::_new_drh ($class, {
Name => "Unify",
Version => $VERSION,
Err => \$DBD::Unify::err,
Errstr => \$DBD::Unify::errstr,
State => \$DBD::Unify::state,
Attribution => "DBD::Unify by H.Merijn Brand",
});
$drh;
} # driver
1;
####### Driver ################################################################
package DBD::Unify::dr;
$DBD::Unify::dr::imp_data_size = 0;
sub connect {
my ($dr_h, $dbname, $user, $auth) = @_;
unless ($ENV{UNIFY} && -d $ENV{UNIFY} && -x _) {
$dr_h->{Warn} and
Carp::croak "\$UNIFY not set or invalid. UNIFY may fail\n";
}
# More checks here if wanted ...
defined $user or $user = "";
defined $auth or $auth = "";
# create a 'blank' dbh
my $dbh = DBI::_new_dbh ($dr_h, {
Name => $dbname,
USER => $user,
CURRENT_USER => $user,
});
# Connect to the database..
DBD::Unify::db::_login ($dbh, $dbname, $user, $auth) or return;
# if ($attr) {
# if ($attr->{dbd_verbose}) {
# $dbh->trace ("DBD");
# }
# }
$dbh;
} # connect
sub data_sources {
my ($dr_h) = @_;
$dr_h->{Warn} and
Carp::carp "\$dr_h->data_sources () not defined for Unify\n";
"";
} # data_sources
1;
####### Database ##############################################################
package DBD::Unify::db;
$DBD::Unify::db::imp_data_size = 0;
sub parse_trace_flag {
my ($dbh, $name) = @_;
# print STDERR "# Flags: $name\n";
return 0x7FFFFF00 if $name eq "DBD"; # $h->trace ("DBD"); -- ALL
# return 0x01000000 if $name eq "select"; # $h->trace ("SQL|select");
# return 0x02000000 if $name eq "update"; # $h->trace ("1|update");
# return 0x04000000 if $name eq "delete";
# return 0x08000000 if $name eq "insert";
return $dbh->SUPER::parse_trace_flag ($name);
} # parse_trace_flag
sub type_info_all {
my ($dbh) = @_;
require DBD::Unify::TypeInfo;
return [ @$DBD::Unify::TypeInfo::type_info_all ];
} # type_info_all
sub get_info {
my ($dbh, $info_type) = @_;
require DBD::Unify::GetInfo;
my $v = $DBD::Unify::GetInfo::info{int $info_type};
ref $v eq "CODE" and $v = $v->($dbh);
return $v;
} # get_info
sub private_attribute_info {
return {
dbd_verbose => undef,
uni_verbose => undef,
uni_unicode => undef,
};
} # private_attribute_info
sub ping {
my $dbh = shift;
$dbh->prepare ("select USER_NAME from SYS.DATABASE_USERS") or return 0;
return 1;
} # ping
sub prepare {
my ($dbh, $statement, @attribs) = @_;
# Strip comments
$statement = join "" => map {
my $s = $_;
$s =~ m/^'.*'$/ or $s =~ s/(--.*)$//m;
$s;
} split m/('[^']*')/ => $statement;
# create a 'blank' sth
my $sth = DBI::_new_sth ($dbh, {
Statement => $statement,
});
# Setup module specific data
# $sth->STORE ("driver_params" => []);
# $sth->STORE ("NUM_OF_PARAMS" => ($statement =~ tr/?//));
DBD::Unify::st::_prepare ($sth, $statement, @attribs) or return;
$sth;
} # prepare
sub _is_or_like {
my ($fld, $val) = @_;
$val =~ m/[_%]/ ? "$fld like '$val'" : "$fld = '$val'";
} # _is_or_like
sub table_info {
my $dbh = shift;
my ($catalog, $schema, $table, $type, $attr);
ref $_[0] or ($catalog, $schema, $table, $type) = splice @_, 0, 4;
if ($attr = shift) {
ref ($attr) eq "HASH" or
Carp::croak qq{usage: table_info ({ TABLE_NAME => "foo", ... })};
exists $attr->{TABLE_SCHEM} and $schema = $attr->{TABLE_SCHEM};
exists $attr->{TABLE_NAME} and $table = $attr->{TABLE_NAME};
exists $attr->{TABLE_TYPE} and $type = $attr->{TABLE_TYPE};
}
if ($catalog) {
$dbh->{Warn} and
Carp::carp "Unify does not support catalogs in table_info\n";
return;
}
my @where;
$schema and push @where, _is_or_like ("OWNR", $schema);
$table and push @where, _is_or_like ("TABLE_NAME", $table);
$type and $type = uc substr $type, 0, 1;
$type and push @where, _is_or_like ("TABLE_TYPE", $type);
local $" = " and ";
my $where = @where ? " where @where" : "";
my $sth = $dbh->prepare (
"select '', OWNR, TABLE_NAME, TABLE_TYPE, RDWRITE ".
"from SYS.ACCESSIBLE_TABLES ".
$where);
$sth or return;
$sth->{ChopBlanks} = 1;
$sth->execute;
$sth;
} # table_info
{ my (%cache, @links, $pki);
sub _sys_clear_cache {
%cache = ();
@links = ();
$pki = undef;
} # _sys_clear_cache
*DBI::db::uni_clear_cache = \&_sys_clear_cache;
sub _set_info_cache {
my $dbh = shift;
keys %cache and return;
my $sth = $dbh->prepare (join " " =>
"select OWNR, TABLE_NAME, COLUMN_NAME, DATA_TYPE, DATA_LENGTH,",
"DATA_SCALE, DISPLAY_LENGTH, DISPLAY_SCALE, NULLABLE,",
"RDNLY, PRIMRY, UNIQ, LOGGED, ORDERED",
"from SYS.ACCESSIBLE_COLUMNS") or return;
$sth->{ChopBlanks} = 1;
$sth->execute or return;
my %sac;
my @fld = @{$sth->{NAME_lc}};
$sth->bind_columns (\@sac{@fld});
while ($sth->fetch) {
$cache{$sac{ownr} || ""}
{$sac{table_name}}
{$sac{column_name}} = [ @sac{@fld} ];
}
} # _set_info_cache
sub _set_link_cache {
my $dbh = shift;
@links and return;
my $sth = $dbh->prepare (join " " =>
"select INDEX_NAME,",
"REFERENCED_OWNER, REFERENCED_TABLE, REFERENCED_COLUMN,",
"REFERENCING_OWNER, REFERENCING_TABLE, REFERENCING_COLUMN,",
"REFERENCING_COLUMN_ORD",
"from SYS.LINK_INDEXES");
$sth or return;
$sth->{ChopBlanks} = 1;
$sth->execute or return;
my %sli;
my @fld = @{$sth->{NAME_lc}};
$sth->bind_columns (\@sli{@fld});
while ($sth->fetch) {
push @links, { %sli };
}
} # _set_link_cache
sub _sys_column_info {
my ($dbh, $sch, $tbl, $col) = @_;
_set_info_cache ($dbh);
my @ci;
foreach my $s (sort keys %cache) {
$sch and lc $sch ne lc $s and next;
foreach my $t (sort keys %{$cache{$s}}) {
$tbl and lc $tbl ne lc $t and next;
foreach my $c (sort keys %{$cache{$s}{$t}}) {
$col and lc $col ne lc $c and next;
push @ci, $cache{$s}{$t}{$c};
}
}
}
@ci;
}
sub _sys_link_info {
my $dbh = shift;
my ($Pcatalog, $Pschema, $Ptable,
$Fcatalog, $Fschema, $Ftable, $attr) = (@_, {});
_set_link_cache ($dbh);
my @fki;
for (@links) {
$Pschema and lc $_->{referenced_owner} ne lc $Pschema and next;
$Ptable and lc $_->{referenced_table} ne lc $Ptable and next;
$Fschema and lc $_->{referencing_owner} ne lc $Fschema and next;
$Ftable and lc $_->{referencing_table} ne lc $Ftable and next;
push @fki, [
undef, @{$_}{qw( referenced_owner referenced_table referenced_column )},
undef, @{$_}{qw( referencing_owner referencing_table referencing_column )},
$_->{referencing_column_ord} + 1,
undef, undef,
$_->{index_name}, undef,
undef, undef,
];
}
@fki;
} # _sys_link_info
sub _sys_primary_keys {
my $dbh = shift;
unless ($pki) {
_set_info_cache ($dbh);
# Note that PRIMRY is *only* set for tables with *ONE* key field
# for composite keys this doesn't work :(
foreach my $s (sort keys %cache) {
foreach my $t (sort keys %{$cache{$s}}) {
foreach my $c (sort keys %{$cache{$s}{$t}}) {
$cache{$s}{$t}{$c}[-4] eq "Y" or next;
push @{$pki->{key}{$s}{$t}}, $c;
}
}
}
# For tables with a combined key, we need to analyse the automatic
# added HASH_INDEX for those tables
if (my $hth = $dbh->prepare (join " " =>
"select OWNR, TABLE_NAME, COLUMN_NAME, COLUMN_ORD",
"from SYS.HASH_INDEXES_G",
"where UNIQUE_SPEC = 'Y'",
"order by OWNR, TABLE_NAME, COLUMN_ORD")) {
$hth->{ChopBlanks} = 1;
$hth->execute or return;
$hth->bind_columns (\my ($sch, $tbl, $fld, $ord));
while ($hth->fetch) {
#warn "$ord $sch.$tbl.$fld\n";
push @{$pki->{key}{$sch}{$tbl}}, $fld;
}
}
}
$pki;
} # _sys_primary_keys
}
sub column_info {
my $dbh = shift;
my ($catalog, $schema, $table, $column);
ref $_[0] or ($catalog, $schema, $table, $column) = splice @_, 0, 4;
if ($catalog) {
$dbh->{Warn} and
Carp::carp "Unify does not support catalogs in column_info\n";
return;
}
my @ci = _sys_column_info ($dbh, $schema, $table, $column) or return;
my @fki;
require DBD::Unify::TypeInfo;
for (@ci) {
my @sli = @$_;
my $uni_type_name = $sli[3];
$uni_type_name =~ s/^CHARACTER$/CHAR/;
$uni_type_name =~ s/^DOUBLE$/DOUBLE PRECISION/;
my $uni_type = DBD::Unify::TypeInfo::uni_type ($uni_type_name);
my $odbc_type = (
$uni_type_name eq "NUMERIC" && $sli[4] <= 4 ? 5 : # SMALLINT
DBD::Unify::_uni2sql_type ($uni_type) ) || 0;
push @fki, [
# TABLE_CAT, TABLE_SCHEM, TABLE_NAME, COLUMN_NAME,
undef, @sli[0..2],
# DATA_TYPE, TYPE_NAME,
$odbc_type, DBD::Unify::TypeInfo::odbc_type ($odbc_type),
# COLUMN_SIZE, BUFFER_LENGTH, DECIMAL_DIGITS, NUM_PREC_RADIX,
$sli[4], undef, $sli[5], undef,
# NULLABLE,
$sli[8] eq "N" ? 0 : $sli[8] eq "Y" ? 1 : 2,
# REMARKS, COLUMN_DEF, SQL_DATA_TYPE, SQL_DATETIME_SUB,
undef, undef, undef, undef,
# CHAR_OCTET_LENGTH, ORDINAL_POSITION, IS_NULLABLE
undef, undef, undef,
# CHAR_SET_CAT, CHAR_SET_SCHEM, CHAR_SET_NAME, COLLATION_CAT,
# COLLATION_SCHEM, COLLATION_NAME, UDT_CAT, UDT_SCHEM, UDT_NAME,
# DOMAIN_CAT, DOMAIN_SCHEM, DOMAIN_NAME, SCOPE_CAT, SCOPE_SCHEM,
# SCOPE_NAME, MAX_CARDINALITY, DTD_IDENTIFIER, IS_SELF_REF,
undef, undef, undef, undef, undef, undef, undef, undef, undef,
undef, undef, undef, undef, undef, undef, undef, undef, undef,
# uni_type, uni_type_name
$uni_type, $uni_type_name,
# uni_display_length, uni_display_scale, uni_rdonly, uni_primry,
# uni_uniq, uni_logged, uni_ordered
@sli[6,7,9..13],
];
}
my @col_name = qw(
TABLE_CAT TABLE_SCHEM TABLE_NAME
COLUMN_NAME DATA_TYPE TYPE_NAME COLUMN_SIZE BUFFER_LENGTH
DECIMAL_DIGITS NUM_PREC_RADIX NULLABLE
REMARKS COLUMN_DEF SQL_DATA_TYPE SQL_DATETIME_SUB CHAR_OCTET_LENGTH
ORDINAL_POSITION IS_NULLABLE
CHAR_SET_CAT CHAR_SET_SCHEM CHAR_SET_NAME COLLATION_CAT COLLATION_SCHEM
COLLATION_NAME UDT_CAT UDT_SCHEM UDT_NAME DOMAIN_CAT DOMAIN_SCHEM
DOMAIN_NAME SCOPE_CAT SCOPE_SCHEM SCOPE_NAME MAX_CARDINALITY
DTD_IDENTIFIER IS_SELF_REF
uni_type uni_type_name
uni_display_length uni_display_scale uni_rdonly uni_primry
uni_uniq uni_logged uni_ordered
);
DBI->connect ("dbi:Sponge:", "", "", {
RaiseError => $dbh->{RaiseError},
PrintError => $dbh->{PrintError},
ChopBlanks => 1,
FetchHashKeyName => $dbh->{FetchHashKeyName} || "NAME",
})->prepare ("select column_info", {
rows => \@fki,
NAME => \@col_name,
});
} # column_info
sub primary_key {
my $dbh = shift;
my ($catalog, $schema, $table) = @_;
if ($catalog) {
$dbh->{Warn} and
Carp::carp "Unify does not support catalogs in table_info\n";
return;
}
# Fetching table information from SYS is *extremely* slow
# Feel free to add your home-grown caching or prepared knowledge here
my @key = eval {
require PROCURA::U2000;
PROCURA::U2000::get_key ($schema, $table);
};
@key and return @key;
my $pki_cache = _sys_primary_keys ($dbh);
$pki_cache && $pki_cache->{key} or return;
foreach my $sch (sort keys %{$pki_cache->{key}}) {
defined $schema && lc $sch ne lc $schema and next;
foreach my $tbl (sort keys %{$pki_cache->{key}{$sch}}) {
defined $table && lc $tbl ne lc $table and next;
push @key, @{$pki_cache->{key}{$sch}{$tbl}};
}
}
return @key;
} # primary_key
sub quote_identifier {
my ($dbh, @arg) = map { defined $_ && $_ ne "" ? $_ : undef } @_;
return $dbh->SUPER::quote_identifier (@arg);
} # quote_identifier
# $sth = $dbh->foreign_key_info (
# $pk_catalog, $pk_schema, $pk_table,
# $fk_catalog, $fk_schema, $fk_table,
# \%attr);
sub foreign_key_info {
my $dbh = shift;
my ($Pcatalog, $Pschema, $Ptable,
$Fcatalog, $Fschema, $Ftable, $attr) = (@_, {});
my @fki = _sys_link_info ($dbh,
$Pcatalog, $Pschema, $Ptable,
$Fcatalog, $Fschema, $Ftable, $attr);
my @col_name = qw(
UK_TABLE_CAT UK_TABLE_SCHEM UK_TABLE_NAME UK_COLUMN_NAME
FK_TABLE_CAT FK_TABLE_SCHEM FK_TABLE_NAME FK_COLUMN_NAME
ORDINAL_POSITION
UPDATE_RULE DELETE_RULE
FK_NAME UK_NAME
DEFERABILITY UNIQUE_OR_PRIMARY );
DBI->connect ("dbi:Sponge:", "", "", {
RaiseError => $dbh->{RaiseError},
PrintError => $dbh->{PrintError},
ChopBlanks => 1,
FetchHashKeyName => $dbh->{FetchHashKeyName} || "NAME",
})->prepare ("select link_info", {
rows => \@fki,
NAME => \@col_name,
});
} # foreign_key_info
# type = "R" ? references me : references
# This is to be converted to foreign_key_info
sub link_info {
my $dbh = shift;
my ($catalog, $schema, $table, $type, $attr);
ref $_[0] or ($catalog, $schema, $table, $type) = splice @_, 0, 4;
if ($attr = shift) {
ref ($attr) eq "HASH" or
Carp::croak qq{usage: link_info ({ TABLE_NAME => "foo", ... })};
exists $attr->{TABLE_SCHEM} and $schema = $attr->{TABLE_SCHEM};
exists $attr->{TABLE_NAME} and $table = $attr->{TABLE_NAME};
exists $attr->{TABLE_TYPE} and $type = $attr->{TABLE_TYPE};
}
my @where;
unless ($type and $type =~ m/^[Rr]/) {
$schema and push @where, "REFERENCING_OWNER = '$schema'";
$table and push @where, "REFERENCING_TABLE = '$table'";
}
else {
$schema and push @where, "REFERENCED_OWNER = '$schema'";
$table and push @where, "REFERENCED_TABLE = '$table'";
}
local $" = " and ";
my $where = @where ? " where @where" : "";
my $sth = $dbh->prepare (join "\n",
"select '', REFERENCED_OWNER, INDEX_NAME, REFERENCED_TABLE,",
" REFERENCED_COLUMN, REFERENCED_COLUMN_ORD,",
" REFERENCING_OWNER, REFERENCING_TABLE, REFERENCING_COLUMN,",
" REFERENCING_COLUMN_ORD ",
"from SYS.LINK_INDEXES",
$where);
$sth or return;
$sth->{ChopBlanks} = 1;
$sth->execute;
$sth;
} # link_info
*DBI::db::link_info = \&link_info;
1;
####### Statement #############################################################
package DBD::Unify::st;
sub private_attribute_info {
return {
uni_type => undef,
};
} # private_attribute_info
1;
####### End ###################################################################
__END__
=head1 DESCRIPTION
DBD::Unify is an extension to Perl which allows access to Unify
databases. It is built on top of the standard DBI extension and
implements the methods that DBI requires.
This document describes the differences between the "generic" DBD
and DBD::Unify.
=head2 Extensions/Changes
=over 2
=item returned types
The DBI docs state that:
Most data is returned to the perl script as strings (null values
are returned as undef). This allows arbitrary precision numeric
data to be handled without loss of accuracy. Be aware that perl
may not preserve the same accuracy when the string is used as a
number.
Integers are returned as integer values (perl's IV's).
(Huge) amounts, floats, reals and doubles are returned as strings for which
numeric context (perl's NV's) has been invoked already, so adding zero to
force convert to numeric context is not needed.
Chars are returned as strings (perl's PV's).
Chars, Dates, Huge Dates and Times are returned as strings (perl's PV's).
Unify represents midnight with 00:00, not 24:00.
=item connect
connect ("DBI:Unify:dbname[;options]" [, user [, auth [, attr]]]);
Options to the connection are passed in the data-source
argument. This argument should contain the database
name possibly followed by a semicolon and the database options
which are ignored.
Since Unify database authorization is done using grant's using the
user name, the I<user> argument may be empty or undef. The I<auth>
field will be used as a default schema. If the I<auth> field is empty
or undefined connect will check for the environment variable $USCHEMA
to use as a default schema. If neither exists, you will end up in your
default schema, or if none is assigned, in the schema PUBLIC.
At the moment none of the attributes documented in DBI's "ATTRIBUTES
COMMON TO ALL HANDLES" are implemented specifically for the Unify
DBD driver, but they might have been inherited from DBI. The I<ChopBlanks>
attribute is implemented, but defaults to 1 for DBD::Unify.
The Unify driver supports "uni_scanlevel" to set the transaction scan
level to a value between 1 and 16 and "uni_verbose" to set DBD specific
debugging, allowing to show only massages from DBD-Unify without using
the default DBI->trace () call.
The connect call will result in statements like:
CONNECT;
SET CURRENT SCHEMA TO PUBLIC; -- if auth = "PUBLIC"
SET TRANSACTION SCAN LEVEL 7; -- if attr has { uni_scanlevel => 7 }
local database
connect ("/data/db/unify/v63AB", "", "SYS")
=item AutoCommit
It is recommended that the C<connect> call ends with the attributes
S<{ AutoCommit => 0 }>, although it is not implemented (yet).
If you don't want to check for errors after B<every> call use
S<{ AutoCommit => 0, RaiseError => 1 }> instead. This will C<die> with
an error message if any DBI call fails.
=item Unicode
By default, this driver is completely Unicode unaware: what you put into
the database will be returned to you without the encoding applied.
To enable automatic decoding of UTF-8 when fetching from the database,
set the C<uni_unicode> attribute to a true value for the database handle
(statement handles will inherit) or to the statement handle.
$dbh->{uni_unicode} = 1;
When CHAR or TEXT fields are retrieved and the content fetched is valid
UTF-8, the value will be marked as such.
=item re-connect
Though both the syntax and the module support connecting to different
databases, even at the same time, the Unify libraries seem to quit
connecting to a new database, even if the old one is closed following
every rule of precaution.
To be safe in closing a handle of all sorts, undef it after it is done with,
it will than be destroyed. (As of 0.12 this is tried internally for handles
that proved to be finished)
explicit:
my $dbh = DBI->connect (...);
my $sth = $dbh->prepare (...);
:
$sth->finish; undef $sth;
$dbh->disconnect; undef $dbh;
or implicit:
{ my $dbh = DBI->connect (...);
{ my $sth = $dbh->prepare (...);
while (my @data = $sth->fetchrow_array) {
:
}
} # $sth implicitly destroyed by end-of-scope
$dbh->disconnect;
} # $dbh implicitly destroyed by end-of-scope
=item do
$dbh->do ($statement)
This is implemented as a call to 'EXECUTE IMMEDIATE' with all the
limitations that this implies.
=item commit and rollback invalidates open cursors
DBD::Unify does warn when a commit or rollback is issued on a $dbh
with open cursors.
Possibly a commit/rollback/disconnect should also undef the $sth's.
(This should probably be done in the DBI-layer as other drivers will
have the same problems).
After a commit or rollback the cursors are all ->finish'ed, i.e. they
are closed and the DBI/DBD will warn if an attempt is made to fetch
from them.
A future version of DBD::Unify might re-prepare the statement.
=back
=head2 Stuff implemented in perl
=over 2
=item driver
Just here for DBI. No use in telling the end-user what to do with it :)
=item connect
=item data_sources
There is no way for Unify to tell what data sources might be available.
There is no central files (like F</etc/oratab> for Oracle) that lists all
available sources, so this method will always return an empty list.
=item quote_identifier
As DBI's C<quote_identifier ()> gladly accepts the empty string as a
valid identifier, I have to override this method to translate empty
strings to undef, so the method behaves properly. Unify does not allow
to select C<NULL> as a constant as in:
select NULL, foo from bar;
=item prepare ($statement [, \%attr])
The only attribute currently supported is the C<dbd_verbose> (or its
alias C<uni_verbose>) level. See "trace" below.
=item table_info ($;$$$$)
=item columne_info ($$$$)
=item foreign_key_info ($$$$$$;$)
=item link_info ($;$$$$)
=item primary_key ($$$)
=item uni_clear_cache ()
Note that these five get their info by accessing the C<SYS> schema which
is relatively extremely slow. e.g. Getting all the primary keys might well
run into seconds, rather than milliseconds.
This is work-in-progress, and we hope to find faster ways to get to this
information. Also note that in order to keep it fast across multiple calls,
some information is cached, so when you alter the data dictionary after a
call to one of these, that cached information is not updated.
For C<column_info ()>, the returned C<DATA_TYPE> is deduced from the
C<TYPE_NAME> returned from C<SYS.ACCESSIBLE_COLUMNS>. The type is in
the ODBC range and the original Unify type and type_name are returned
in the additional fields C<uni_type> and C<uni_type_name>. Somehow
selecting from that table does not return valid statement handles for
types C<currency> and C<huge integer>.
Create as sth attributes uni_type/uni_type_name
------------------- ------------------- -------------------------
amount FLOAT 6 -4 AMOUNT (9, 2)
amount (5, 2) FLOAT 6 -4 AMOUNT (5, 2)
huge amount REAL 7 -6 HUGE AMOUNT (15, 2)
huge amount (5, 2) REAL 7 -6 HUGE AMOUNT (5, 2)
huge amount (15, 2) REAL 7 -6 HUGE AMOUNT (15, 2)
byte BINARY -2 -12 BYTE (1)
byte (512) BINARY -2 -12 BYTE (512)
char CHAR 1 1 CHAR (1)
char (12) CHAR 1 1 CHAR (12)
currency DECIMAL 3 - ?
currency (9) DECIMAL 3 - ?
currency (7,2) DECIMAL 3 - ?
date DATE 9 -3 DATE
huge date TIMESTAMP 11 -11 HUGE DATE
decimal NUMERIC 2 2 NUMERIC (9)
decimal (2) NUMERIC 2 2 NUMERIC (2)
decimal (8) NUMERIC 2 2 NUMERIC (8)
double precision DOUBLE PRECISION 8 8 DOUBLE PRECISION (64)
float DOUBLE PRECISION 8 6 FLOAT (64)
huge integer HUGE INTEGER -5 - ?
integer NUMERIC 2 2 NUMERIC (9)
numeric NUMERIC 2 2 NUMERIC (9)
numeric (2) SMALLINT 5 2 NUMERIC (2)
numeric (6) NUMERIC 2 2 NUMERIC (6)
real REAL 7 7 REAL (32)
smallint SMALLINT 5 2 NUMERIC (4)
text TEXT -1 -9 TEXT
time TIME 10 -7 TIME
Currently the driver tries to cache information about the schema as it
is required. When there are fields added, removed, or altered, references
are added or removed or primary keys or unique hashes are added or removed
it is wise to call C<< $dbh->uni_clear_cache >> to ensure that the info
on next inquiries will be up to date.
=item ping
=back
=head2 Stuff implemented in C (XS)
=over 2
=item trace
The C<DBI-E<gt>trace (level)> call will promote the level to DBD::Unify,
showing both the DBI layer debugging messages as well as the DBD::Unify
specific driver-side debug messages.
It is however also possible to trace B<only> the DBD-Unify without the
C<DBI-E<gt>trace ()> call by using the C<uni_verbose> attribute on C<connect ()>
or by setting it later to the database handle, the default level is set from
the environment variable C<$DBD_TRACE> if defined:
$dbh = DBI->connect ("DBI::Unify", "", "", { uni_verbose => 3 });
$dbh->{uni_verbose} = 3;
As DBD::Oracle also supports this scheme since version 1.22, C<dbd_verbose>
is a portable alias for C<uni_verbose>, which is also supported in DBD::Oracle.
DBD::Unify now also allows an even finer grained debugging, by allowing
C<dbd_verbose> on statement handles too. The default C<dbd_verbose> for
statement handles is the global C<dbd_verbose> at creation time of the
statement handle.
The environment variable C<DBD_VERBOSE> is used if defined and overrules
C<$DBD_TRACE>.
$dbh->{dbd_verbose} = 4;
$sth = $dbh->prepare ("select * from foo"); # sth's dbd_verbose = 4
$dbh->{dbd_verbose} = 3; # sth's dbd_verbose = 4
$sth->{dbd_verbose} = 5; # now 5
Currently, the following levels are defined:
=over 2
=item 1 & 2
No DBD messages implemented at level 1 and 2, as they are reserved for DBI
=item Z<>3
DBD::Unify::dbd_db_STORE (ScanLevel = 7)
DBD::Unify::st_prepare u_sql_00_000000 ("select * from foo")
DBD::Unify::st_prepare u_sql_00_000000 (<= 4, => 0)
DBD::Unify::st_execute u_sql_00_000000
DBD::Unify::st_destroy 'select * from parm'
DBD::Unify::st_free u_sql_00_000000
DBD::Unify::st 0x7F7F25CC 0x0000 0x0000 0x00000000 0x00000000 0x00000000
DBD::Unify::st destroyed
DBD::Unify::db_disconnect
DBD::Unify::db_destroy
=item Z<>4
Level 3 plus errors and additional return codes and field types and values:
DBD::Unify::st_prepare u_sql_00_000000 ("select c_bar from foo where c_foo = 1")
After allocate, sqlcode = 0
After prepare, sqlcode = 0
After allocate, sqlcode = 0
After describe, sqlcode = 0
After count, sqlcode = 0, count = 1
DBD::Unify::fld_describe o_sql_00_000000 (1 fields)
After get, sqlcode = 0
DBD::Unify::st_prepare u_sql_00_000000 (<= 1, => 0)
DBD::Unify::st_execute u_sql_00_000000
After open, sqlcode = 0 (=> 0)
DBD::Unify::st_fetch u_sql_00_000000
Fetched sqlcode = 0, fields = 1
After get, sqlcode = 0
Field 1: c_bar: NUMERIC 4: (6030) 6030 ==
Fetch done
DBD::Unify::st_finish u_sql_00_000000
After close, sqlcode = 0
DBD::Unify::st_destroy 'select c_bar from foo where c_foo = 1'
DBD::Unify::st_free u_sql_00_000000
After deallocO, sqlcode = 0
After deallocU, sqlcode = 0
=item Z<>5
Level 4 plus some content info:
DBD::Unify::st_fetch u_sql_00_000000
Fetched sqlcode = 0, fields = 1
After get, sqlcode = 0
Field 1: [05 00 04 00 00] c_bar: NUMERIC 4: (6030) 6030 ==
Fetch done
=item Z<>6
Level 5 plus internal coding for exchanges and low(er) level return codes:
DBD::Unify::fld_describe o_sql_00_000000 (1 fields)
After get, sqlcode = 0
Field 1: [05 00 04 00 FFFFFFFF] c_bar
DBD::Unify::st_prepare u_sql_00_000000 (<= 1, => 0)
=item Z<>7
Level 6 plus destroy/cleanup states:
DBD::Unify::st_free u_sql_00_000000
destroy allocc destroy alloco After deallocO, sqlcode = 0
destroy alloci destroy allocp After deallocU, sqlcode = 0
destroy stat destroy growup destroy impset
=item Z<>8
No messages (yet) set to level 8 and up.
=back
=item int dbd_bind_ph (SV *sth, imp_sth_t *imp_sth, SV *param, SV *value, IV sql_type, SV *attribs, int is_inout, IV maxlen)
=item SV *dbd_db_FETCH_attrib (SV *dbh, imp_dbh_t *imp_dbh, SV *keysv)
=item int dbd_db_STORE_attrib (SV *dbh, imp_dbh_t *imp_dbh, SV *keysv, SV *valuesv)
=item int dbd_db_commit (SV *dbh, imp_dbh_t *imp_dbh)
=item void dbd_db_destroy (SV *dbh, imp_dbh_t *imp_dbh)
=item int dbd_db_disconnect (SV *dbh, imp_dbh_t *imp_dbh)
=item int dbd_db_do (SV *dbh, char *statement)
=item int dbd_db_login (SV *dbh, imp_dbh_t *imp_dbh, char *dbname, char *user, char *pwd)
=item int dbd_db_rollback (SV *dbh, imp_dbh_t *imp_dbh)
=item int dbd_discon_all (SV *drh, imp_drh_t *imp_drh)
=item int dbd_fld_describe (SV *dbh, imp_sth_t *imp_sth, int num_fields)
=item void dbd_init (dbistate_t *dbistate)
=item int dbd_prm_describe (SV *dbh, imp_sth_t *imp_sth, int num_params)
=item SV *dbd_st_FETCH_attrib (SV *sth, imp_sth_t *imp_sth, SV *keysv)
=item int dbd_st_STORE_attrib (SV *sth, imp_sth_t *imp_sth, SV *keysv, SV *valuesv)
=item int dbd_st_blob_read (SV *sth, imp_sth_t *imp_sth, int field, long offset, long len, SV *destrv, long destoffset)
=item void dbd_st_destroy (SV *sth, imp_sth_t *imp_sth)
=item int dbd_st_execute (SV *sth, imp_sth_t *imp_sth)
=item AV *dbd_st_fetch (SV *sth, imp_sth_t *imp_sth)
=item int dbd_st_finish (SV *sth, imp_sth_t *imp_sth)
=item int dbd_st_prepare (SV *sth, imp_sth_t *imp_sth, char *statement, SV *attribs)
=item int dbd_st_rows (SV *sth, imp_sth_t *imp_sth)
=back
=head1 TODO
As this module is probably far from complete, so will the TODO list most
likely will be far from complete. More generic (test) items are mentioned
in the README in the module distribution.
=over 4
=item Handle attributes
Check if all documented handle (database- and statement-) attributes are
supported and work as expected.
local $dbh->{RaiseError} = 0;
local $sth->{FetchHashKeyName} = "NAME";
=item Statement attributes
Allow setting and getting statement attributes. A specific example might be
$sth->{PrintError} = 0;
$sth->{FetchHashKeyName} = "NAME_uc";
=item 3-argument bind_param ()
Investigate and implement 3-argument versions of $sth->bind_param ()
=item looks_as_number ()
Investigate if looks_as_number () should be used in st_bind ().
Comments are in where it should.
=item Multiple open databases
Try finding a way to open several different Unify databases at the
same time for parallel (or at least sequential) processing.
=back
=head1 SEE ALSO
The DBI documentation in L<DBI>, a lot of web pages, some very good, the
Perl 5 DBI Home page (http://dbi.perl.org/), other DBD modules'
documentation (DBD-Oracle is probably the most complete), the
comp.lang.perl.modules newsgroup and the dbi-users mailing list
(mailto:dbi-users-help@perl.org)
=head1 AUTHOR
DBI/DBD was developed by Tim Bunce, who also developed the DBD::Oracle.
H.Merijn Brand developed the DBD::Unify extension.
Todd Zervas has given a lot of feedback and patches.
=head1 COPYRIGHT AND LICENSE
Copyright (C) 1999-2017 H.Merijn Brand
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut