Bug 310717: [Oracle] Bugzilla::DB::Oracle module

Bug 310718: [Oracle] Bugzilla::DB::Schema::Oracle module
Patch By Xiaoou Wu <xiaoou.wu@oracle.com> r=mkanat, a=mkanat

6 files changed, 762 insertions, 57 deletions

diff --git a/Bugzilla/Constants.pm b/Bugzilla/Constants.pm
index e34fc0bb7..3c02c3902 100644
--- a/Bugzilla/Constants.pm
+++ b/Bugzilla/Constants.pm
@@ -395,6 +395,13 @@ use constant DB_MODULE => {
                     version => '1.45',
                 },
                 name => 'PostgreSQL'},
+     'oracle'=> {db => 'Bugzilla::DB::Oracle', db_version => '10.01.0',
+                dbd => {
+                     package => 'DBD-Oracle',
+                     module  => 'DBD::Oracle',
+                     version => '1.19',
+                },
+                name => 'Oracle'},
 };
 
 # The user who should be considered "root" when we're giving
diff --git a/Bugzilla/DB.pm b/Bugzilla/DB.pm
index 4aad803c6..49692eec0 100644
--- a/Bugzilla/DB.pm
+++ b/Bugzilla/DB.pm
@@ -301,6 +301,62 @@ sub import {
     $Exporter::ExportLevel-- if $is_exporter;
 }
 
+sub bz_lock_tables {
+    my ($self, @tables) = @_;
+
+    my $list = join(', ', @tables);
+    # Check first if there was no lock before
+    if ($self->{private_bz_tables_locked}) {
+        ThrowCodeError("already_locked", { current => $self->{private_bz_tables_locked},
+                                           new => $list });
+    } else {
+        my %read_tables;
+        my %write_tables;
+        foreach my $table (@tables) {
+            $table =~ /^([\d\w]+)([\s]+AS[\s]+[\d\w]+)?[\s]+(WRITE|READ)$/i;
+            my $table_name = $1;
+            if ($3 =~ /READ/i) {
+                if (!exists $read_tables{$table_name}) {
+                    $read_tables{$table_name} = undef;
+                }
+            }
+            else {
+                if (!exists $write_tables{$table_name}) {
+                    $write_tables{$table_name} = undef;
+                }
+            }
+        }
+
+        # Begin Transaction
+        $self->bz_start_transaction();
+
+        Bugzilla->dbh->do('LOCK TABLE ' . join(', ', keys %read_tables) .
+                          ' IN ROW SHARE MODE') if keys %read_tables;
+        Bugzilla->dbh->do('LOCK TABLE ' . join(', ', keys %write_tables) .
+                          ' IN ROW EXCLUSIVE MODE') if keys %write_tables;
+        $self->{private_bz_tables_locked} = $list;
+    }
+}
+
+sub bz_unlock_tables {
+    my ($self, $abort) = @_;
+
+    # Check first if there was previous matching lock
+    if (!$self->{private_bz_tables_locked}) {
+        # Abort is allowed even without previous lock for error handling
+        return if $abort;
+        ThrowCodeError("no_matching_lock");
+    } else {
+        $self->{private_bz_tables_locked} = "";
+        # End transaction, tables will be unlocked automatically
+        if ($abort) {
+            $self->bz_rollback_transaction();
+        } else {
+            $self->bz_commit_transaction();
+        }
+    }
+}
+
 sub sql_istrcmp {
     my ($self, $left, $right, $op) = @_;
     $op ||= "=";
diff --git a/Bugzilla/DB/Oracle.pm b/Bugzilla/DB/Oracle.pm
new file mode 100644
index 000000000..008f4be70
--- /dev/null
+++ b/Bugzilla/DB/Oracle.pm
@@ -0,0 +1,487 @@
+# -*- Mode: perl; indent-tabs-mode: nil -*-
+#
+# The contents of this file are subject to the Mozilla Public
+# License Version 1.1 (the "License"); you may not use this file
+# except in compliance with the License. You may obtain a copy of
+# the License at http://www.mozilla.org/MPL/
+#
+# Software distributed under the License is distributed on an "AS
+# IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# rights and limitations under the License.
+#
+# The Original Code is the Bugzilla Bug Tracking System.
+#
+# The Initial Developer of the Original Code is Oracle Corporation. 
+# Portions created by Oracle are Copyright (C) 2007 Oracle Corporation. 
+# All Rights Reserved.
+#
+# Contributor(s): Lance Larsh <lance.larsh@oracle.com>
+#                 Xiaoou Wu   <xiaoou.wu@oracle.com>
+#                 Max Kanat-Alexander <mkanat@bugzilla.org>
+
+=head1 NAME
+
+Bugzilla::DB::Oracle - Bugzilla database compatibility layer for Oracle
+
+=head1 DESCRIPTION
+
+This module overrides methods of the Bugzilla::DB module with Oracle
+specific implementation. It is instantiated by the Bugzilla::DB module
+and should never be used directly.
+
+For interface details see L<Bugzilla::DB> and L<DBI>.
+
+=cut
+
+package Bugzilla::DB::Oracle;
+
+use strict;
+
+use DBD::Oracle;
+use DBD::Oracle qw(:ora_types);
+use Bugzilla::Constants;
+use Bugzilla::Error;
+use Bugzilla::Util;
+# This module extends the DB interface via inheritance
+use base qw(Bugzilla::DB);
+
+#####################################################################
+# Constants
+#####################################################################
+use constant EMPTY_STRING  => '__BZ_EMPTY_STR__';
+use constant ISOLATION_LEVEL => 'SERIALIZABLE';
+use constant BLOB_TYPE => { ora_type => ORA_BLOB };
+
+sub new {
+    my ($class, $user, $pass, $host, $dbname, $port) = @_;
+
+    # You can never connect to Oracle without a DB name,
+    # and there is no default DB.
+    $dbname ||= Bugzilla->localconfig->{db_name};
+
+    # Set the language enviroment
+    $ENV{'NLS_LANG'} = '.AL32UTF8' if Bugzilla->params->{'utf8'};
+
+    # construct the DSN from the parameters we got
+    my $dsn = "DBI:Oracle:host=$host;sid=$dbname";
+    $dsn .= ";port=$port" if $port;
+    my $attrs = { FetchHashKeyName => 'NAME_lc',  
+                  LongReadLen => ( Bugzilla->params->{'maxattachmentsize'}
+                                     || 1000 ) * 1024, 
+                };
+    my $self = $class->db_new($dsn, $user, $pass, $attrs);
+
+    bless ($self, $class);
+
+    # Set the session's default date format to match MySQL
+    $self->do("ALTER SESSION SET NLS_DATE_FORMAT='YYYY-MM-DD HH24:MI:SS'");
+    $self->do("ALTER SESSION SET NLS_TIMESTAMP_FORMAT='YYYY-MM-DD HH24:MI:SS'");
+    $self->do("ALTER SESSION SET NLS_LENGTH_SEMANTICS='CHAR'") 
+        if Bugzilla->params->{'utf8'};
+    return $self;
+}
+
+sub bz_last_key {
+    my ($self, $table, $column) = @_;
+
+    my $seq = $table . "_" . $column . "_SEQ";
+    my ($last_insert_id) = $self->selectrow_array("SELECT $seq.CURRVAL "
+                                                  . " FROM DUAL");
+    return $last_insert_id;
+}
+
+sub sql_regexp {
+    my ($self, $expr, $pattern) = @_;
+
+    return "REGEXP_LIKE($expr, $pattern)";
+}
+
+sub sql_not_regexp {
+    my ($self, $expr, $pattern) = @_;
+
+    return "NOT REGEXP_LIKE($expr, $pattern)" 
+}
+
+sub sql_limit {
+    my ($self, $limit, $offset) = @_;
+
+    if(defined $offset) {
+        return  "/* LIMIT $limit $offset */";
+    }
+    return "/* LIMIT $limit */";
+}
+
+sub sql_string_concat {
+    my ($self, @params) = @_;
+
+    return 'CONCAT(' . join(', ', @params) . ')';
+}
+
+sub sql_to_days {
+    my ($self, $date) = @_;
+
+    return " TO_CHAR(TO_DATE($date),'J') ";
+}
+sub sql_from_days{
+    my ($self, $date) = @_;
+
+    return " TO_DATE($date,'J') ";
+}
+sub sql_fulltext_search {
+    my ($self, $column, $text) = @_;
+    $text = $self->quote($text);
+    trick_taint($text);
+    return "CONTAINS($column,$text)";
+}
+
+sub sql_date_format {
+    my ($self, $date, $format) = @_;
+    
+    $format = "%Y.%m.%d %H:%i:%s" if !$format;
+
+    $format =~ s/\%Y/YYYY/g;
+    $format =~ s/\%y/YY/g;
+    $format =~ s/\%m/MM/g;
+    $format =~ s/\%d/DD/g;
+    $format =~ s/\%a/Dy/g;
+    $format =~ s/\%H/HH24/g;
+    $format =~ s/\%i/MI/g;
+    $format =~ s/\%s/SS/g;
+
+    return "TO_CHAR($date, " . $self->quote($format) . ")";
+}
+
+sub sql_interval {
+    my ($self, $interval, $units) = @_;
+
+    return "INTERVAL " . $self->quote($interval) . " $units";
+}
+
+sub sql_position {
+    my ($self, $fragment, $text) = @_;
+    return "INSTR($text, $fragment)";
+}
+sub _fix_empty {
+    my ($string) = @_;
+    $string = '' if $string eq EMPTY_STRING;
+    return $string;
+}
+
+sub _fix_arrayref {
+    my ($row) = @_;
+    return undef if !defined $row;
+    foreach my $field (@$row) {
+        $field = _fix_empty($field) if defined $field;
+    }
+    return $row;
+}
+
+sub _fix_hashref {
+     my ($row) = @_;
+     return undef if !defined $row;
+     foreach my $value (values %$row) {
+       $value = _fix_empty($value) if defined $value;
+     }
+     return $row;
+}
+
+sub adjust_statement {
+    my ($sql) = @_;
+
+    # We can't just assume any occurrence of "''" in $sql is an empty
+    # string, since "''" can occur inside a string literal as a way of
+    # escaping a single "'" in the literal.  Therefore we must be trickier...
+
+    # split the statement into parts by single-quotes.  The negative value
+    # at the end to the split operator from dropping trailing empty strings
+    # (e.g., when $sql ends in "''")
+    my @parts = split /'/, $sql, -1;
+
+    if( !(@parts % 2) ) {
+        # Either the string is empty or the quotes are mismatched
+        # Returning input unmodified.
+        return $sql;
+    }
+
+    # We already verified that we have an odd number of parts.  If we take
+    # the first part off now, we know we're entering the loop with an even
+    # number of parts
+    my @result;
+    my $part = shift @parts;
+    
+    # Oracle requires a FROM clause in all SELECT statements, so append
+    # "FROM dual" to queries without one (e.g., "SELECT NOW()")
+    my $is_select = ($part =~ m/^\s*SELECT\b/io);
+    my $has_from =  ($part =~ m/\bFROM\b/io) if $is_select;
+
+    # Oracle recognizes CURRENT_DATE, but not CURRENT_DATE()
+    $part =~ s/\bCURRENT_DATE\b\(\)/CURRENT_DATE/io;
+    
+    # Oracle use SUBSTR instead of SUBSTRING
+    $part =~ s/\bSUBSTRING\b/SUBSTR/io;
+   
+    # Oracle need no 'AS'
+    $part =~ s/\bAS\b//ig;
+    
+    # Oracle doesn't have LIMIT, so if we find the LIMIT comment, wrap the
+    # query with "SELECT * FROM (...) WHERE rownum < $limit"
+    my ($limit,$offset) = ($part =~ m{/\* LIMIT (\d*) (\d*) \*/}o);
+    
+    push @result, $part;
+    while( @parts ) {
+        my $string = shift @parts;
+        my $nonstring = shift @parts;
+    
+        # if the non-string part is zero-length and there are more parts left,
+        # then this is an escaped quote inside a string literal   
+        while( !(length $nonstring) && @parts  ) {
+            # we know it's safe to remove two parts at a time, since we
+            # entered the loop with an even number of parts
+            $string .= "''" . shift @parts;
+            $nonstring = shift @parts;
+        }
+
+        # Look for a FROM if this is a SELECT and we haven't found one yet
+        $has_from = ($nonstring =~ m/\bFROM\b/io) 
+                    if ($is_select and !$has_from);
+
+        # Oracle recognizes CURRENT_DATE, but not CURRENT_DATE()
+        $nonstring =~ s/\bCURRENT_DATE\b\(\)/CURRENT_DATE/io;
+
+        # Oracle use SUBSTR instead of SUBSTRING
+        $nonstring =~ s/\bSUBSTRING\b/SUBSTR/io;
+        
+        # Oracle need no 'AS'
+        $nonstring =~ s/\bAS\b//ig;
+
+        # Look for a LIMIT clause
+        ($limit) = ($nonstring =~ m(/\* LIMIT (\d*) \*/)o);
+
+        push @result, $string;
+        push @result, $nonstring;
+    }
+
+    my $new_sql = join "'", @result;
+
+    # Append "FROM dual" if this is a SELECT without a FROM clause
+    $new_sql .= " FROM DUAL" if ($is_select and !$has_from);
+
+    # Wrap the query with a "WHERE rownum <= ..." if we found LIMIT
+    
+    if (defined($limit)) {
+        if ($new_sql !~ /\bWHERE\b/) {
+            $new_sql = $new_sql." WHERE 1=1";
+        }
+         my ($before_where, $after_where) = split /\bWHERE\b/i,$new_sql;
+         if (defined($offset)) {
+             if ($new_sql =~ /(.*\s+)FROM(\s+.*)/i) { 
+                 my ($before_from,$after_from) = ($1,$2);
+                 $before_where = "$before_from FROM ($before_from,"
+                              . " ROW_NUMBER() OVER (ORDER BY quipid) R "
+                              . " FROM $after_from ) "; 
+                 $after_where = " R BETWEEN $offset+1 AND $limit+$offset";
+             }
+         } else {
+                 $after_where = " rownum <=$limit AND ".$after_where;
+         }
+
+         $new_sql = $before_where." WHERE ".$after_where;
+    }
+    return $new_sql;
+}
+
+sub do {
+    my $self = shift;
+    my $sql  = shift;
+    $sql = adjust_statement($sql);
+    unshift @_, $sql;
+    return $self->SUPER::do(@_);
+}
+
+sub selectrow_array {
+    my $self = shift;
+    my $stmt = shift;
+    my $new_stmt = (ref $stmt) ? $stmt : adjust_statement($stmt);
+    unshift @_, $new_stmt;
+    if ( wantarray ) {
+        my @row = $self->SUPER::selectrow_array(@_);
+        _fix_arrayref(\@row);
+        return @row;
+    } else {
+        my $row = $self->SUPER::selectrow_array(@_);
+        $row = _fix_empty($row) if defined $row;
+        return $row;
+    }
+}
+
+sub selectrow_arrayref {
+    my $self = shift;
+    my $stmt = shift;
+    my $new_stmt = (ref $stmt) ? $stmt : adjust_statement($stmt);
+    unshift @_, $new_stmt;
+    my $ref = $self->SUPER::selectrow_arrayref(@_);
+    return undef if !defined $ref;
+
+    _fix_arrayref($ref);
+    return $ref;
+}
+
+sub selectrow_hashref {
+    my $self = shift;
+    my $stmt = shift;
+    my $new_stmt = (ref $stmt) ? $stmt : adjust_statement($stmt);
+    unshift @_, $new_stmt;
+    my $ref = $self->SUPER::selectrow_hashref(@_);
+    return undef if !defined $ref;
+
+    _fix_hashref($ref);
+    return $ref;
+}
+
+sub selectall_arrayref {
+    my $self = shift;
+    my $stmt = shift;
+    my $new_stmt = (ref $stmt) ? $stmt : adjust_statement($stmt);
+    unshift @_, $new_stmt;
+    my $ref = $self->SUPER::selectall_arrayref(@_);
+    return undef if !defined $ref;
+    
+    foreach my $row (@$ref) {
+       if (ref($row) eq 'ARRAY') {
+            _fix_arrayref($row);
+       }
+       elsif (ref($row) eq 'HASH') {
+            _fix_hashref($row);
+       }
+    }
+
+    return $ref;
+}
+
+sub selectall_hashref {
+    my $self = shift;
+    my $stmt = shift;
+    my $new_stmt = (ref $stmt) ? $stmt : adjust_statement($stmt);
+    unshift @_, $new_stmt;
+    my $rows = $self->SUPER::selectall_hashref(@_);
+    return undef if !defined $rows;
+    foreach my $row (values %$rows) { 
+          _fix_hashref($row);
+    }
+    return $rows;
+}
+
+sub selectcol_arrayref {
+    my $self = shift;
+    my $stmt = shift;
+    my $new_stmt = (ref $stmt) ? $stmt : adjust_statement($stmt);
+    unshift @_, $new_stmt;
+    my $ref = $self->SUPER::selectcol_arrayref(@_);
+    return undef if !defined $ref;
+    _fix_arrayref($ref);
+    return $ref;
+}
+
+sub prepare {
+    my $self = shift;
+    my $sql  = shift;
+    my $new_sql = adjust_statement($sql);
+    unshift @_, $new_sql;
+    return bless $self->SUPER::prepare(@_),
+                        'Bugzilla::DB::Oracle::st';
+}
+
+sub prepare_cached {
+    my $self = shift;
+    my $sql  = shift;
+    my $new_sql = adjust_statement($sql);
+    unshift @_, $new_sql;
+    return bless $self->SUPER::prepare_cached(@_),
+                      'Bugzilla::DB::Oracle::st';
+}
+
+sub quote_identifier {
+     my ($self,$id) = @_;
+     return $id;
+}
+
+
+
+#####################################################################
+# Custom Database Setup
+#####################################################################
+
+sub bz_setup_database {
+    my $self = shift;
+    
+    # Create a function that returns SYSDATE to emulate MySQL's "NOW()".
+    # Function NOW() is used widely in Bugzilla SQLs, but Oracle does not 
+    # have that function, So we have to create one ourself. 
+    $self->do("CREATE OR REPLACE FUNCTION NOW "
+              . " RETURN DATE IS BEGIN RETURN SYSDATE; END;");
+    # Create a WORLD_LEXER named BZ_LEX for multilingual fulltext search
+    $self->do("BEGIN CTX_DDL.CREATE_PREFERENCE
+                        ('BZ_LEX', 'WORLD_LEXER'); END;");
+
+    $self->SUPER::bz_setup_database(@_);
+}
+
+package Bugzilla::DB::Oracle::st;
+use base qw(DBD::Oracle::st);
+ 
+sub fetchrow_arrayref {
+    my $self = shift;
+    my $ref = $self->SUPER::fetchrow_arrayref(@_);
+    return undef if !defined $ref;
+    Bugzilla::DB::Oracle::_fix_arrayref($ref);
+    return $ref;
+}
+
+sub fetchrow_array {
+    my $self = shift;
+    if ( wantarray ) {
+        my @row = $self->SUPER::fetchrow_array(@_);
+        Bugzilla::DB::Oracle::_fix_arrayref(\@row);
+        return @row;
+    } else {
+        my $row = $self->SUPER::fetchrow_array(@_);
+        $row = Bugzilla::DB::Oracle::_fix_empty($row) if defined $row;
+        return $row;
+    }
+}
+
+sub fetchrow_hashref {
+    my $self = shift;
+    my $ref = $self->SUPER::fetchrow_hashref(@_);
+    return undef if !defined $ref;
+    Bugzilla::DB::Oracle::_fix_hashref($ref);
+    return $ref;
+}
+
+sub fetchall_arrayref {
+    my $self = shift;
+    my $ref = $self->SUPER::fetchall_arrayref(@_);
+    return undef if !defined $ref;
+    foreach my $row (@$ref) {
+        if (ref($row) eq 'ARRAY') {
+             Bugzilla::DB::Oracle::_fix_arrayref($row);
+        }
+        elsif (ref($row) eq 'HASH') {
+            Bugzilla::DB::Oracle::_fix_hashref($row);
+        }
+    }
+    return $ref;
+}
+
+sub fetchall_hashref {
+    my $self = shift;
+    my $ref = $self->SUPER::fetchall_hashref(@_);
+    return undef if !defined $ref;
+    foreach my $row (values %$ref) {
+         Bugzilla::DB::Oracle::_fix_hashref($row);
+    }
+     return $ref;
+}
+    
+1;
diff --git a/Bugzilla/DB/Pg.pm b/Bugzilla/DB/Pg.pm
index bd16b654c..9675e1f26 100644
--- a/Bugzilla/DB/Pg.pm
+++ b/Bugzilla/DB/Pg.pm
@@ -158,62 +158,6 @@ sub sql_string_concat {
     return '(CAST(' . join(' AS text) || CAST(', @params) . ' AS text))';
 }
 
-sub bz_lock_tables {
-    my ($self, @tables) = @_;
-   
-    my $list = join(', ', @tables);
-    # Check first if there was no lock before
-    if ($self->{private_bz_tables_locked}) {
-        ThrowCodeError("already_locked", { current => $self->{private_bz_tables_locked},
-                                           new => $list });
-    } else {
-        my %read_tables;
-        my %write_tables;
-        foreach my $table (@tables) {
-            $table =~ /^([\d\w]+)([\s]+AS[\s]+[\d\w]+)?[\s]+(WRITE|READ)$/i;
-            my $table_name = $1;
-            if ($3 =~ /READ/i) {
-                if (!exists $read_tables{$table_name}) {
-                    $read_tables{$table_name} = undef;
-                }
-            }
-            else {
-                if (!exists $write_tables{$table_name}) {
-                    $write_tables{$table_name} = undef;
-                }
-            }
-        }
-    
-        # Begin Transaction
-        $self->bz_start_transaction();
-        
-        Bugzilla->dbh->do('LOCK TABLE ' . join(', ', keys %read_tables) .
-                          ' IN ROW SHARE MODE') if keys %read_tables;
-        Bugzilla->dbh->do('LOCK TABLE ' . join(', ', keys %write_tables) .
-                          ' IN ROW EXCLUSIVE MODE') if keys %write_tables;
-        $self->{private_bz_tables_locked} = $list;
-    }
-}
-
-sub bz_unlock_tables {
-    my ($self, $abort) = @_;
-    
-    # Check first if there was previous matching lock
-    if (!$self->{private_bz_tables_locked}) {
-        # Abort is allowed even without previous lock for error handling
-        return if $abort;
-        ThrowCodeError("no_matching_lock");
-    } else {
-        $self->{private_bz_tables_locked} = "";
-        # End transaction, tables will be unlocked automatically
-        if ($abort) {
-            $self->bz_rollback_transaction();
-        } else {
-            $self->bz_commit_transaction();
-        }
-    }
-}
-
 # Tell us whether or not a particular sequence exists in the DB.
 sub bz_sequence_exists {
     my ($self, $seq_name) = @_;
diff --git a/Bugzilla/DB/Schema.pm b/Bugzilla/DB/Schema.pm
index a4c1019b8..89ae99a62 100644
--- a/Bugzilla/DB/Schema.pm
+++ b/Bugzilla/DB/Schema.pm
@@ -206,6 +206,7 @@ update this column in this table."
 =cut
 
 use constant SCHEMA_VERSION  => '2.00';
+use constant ADD_COLUMN      => 'ADD COLUMN';
 use constant ABSTRACT_SCHEMA => {
 
     # BUG-RELATED TABLES
@@ -1750,7 +1751,7 @@ sub get_add_column_ddl {
 
     my ($self, $table, $column, $definition, $init_value) = @_;
     my @statements;
-    push(@statements, "ALTER TABLE $table ADD COLUMN $column " .
+    push(@statements, "ALTER TABLE $table". ADD_COLUMN ." $column " .
         $self->get_type_ddl($definition));
 
     # XXX - Note that although this works for MySQL, most databases will fail
diff --git a/Bugzilla/DB/Schema/Oracle.pm b/Bugzilla/DB/Schema/Oracle.pm
new file mode 100644
index 000000000..fef970c8e
--- /dev/null
+++ b/Bugzilla/DB/Schema/Oracle.pm
@@ -0,0 +1,210 @@
+# -*- Mode: perl; indent-tabs-mode: nil -*-
+#
+# The contents of this file are subject to the Mozilla Public
+# License Version 1.1 (the "License"); you may not use this file
+# except in compliance with the License. You may obtain a copy of
+# the License at http://www.mozilla.org/MPL/
+#
+# Software distributed under the License is distributed on an "AS
+# IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# rights and limitations under the License.
+#
+# The Original Code is the Bugzilla Bug Tracking System.
+#
+# The Initial Developer of the Original Code is Oracle Corporation.
+# Portions created by Oracle are Copyright (C) 2007 Oracle Corporation.
+# All Rights Reserved.
+#
+# Contributor(s): Lance Larsh <lance.larsh@oracle.com>
+#                 Xiaoou Wu <xiaoou.wu@oracle.com>
+#                 Max Kanat-Alexander <mkanat@bugzilla.org>
+
+package Bugzilla::DB::Schema::Oracle;
+
+###############################################################################
+#
+# DB::Schema implementation for Oracle
+#
+###############################################################################
+
+use strict;
+
+use base qw(Bugzilla::DB::Schema);
+use Carp qw(confess);
+use Digest::MD5  qw(md5_hex);
+use Bugzilla::Util;
+
+use constant ADD_COLUMN      => 'ADD';
+
+#------------------------------------------------------------------------------
+sub _initialize {
+
+    my $self = shift;
+
+    $self = $self->SUPER::_initialize(@_);
+
+    $self->{db_specific} = {
+
+        BOOLEAN =>      'integer',
+        FALSE =>        '0', 
+        TRUE =>         '1',
+
+        INT1 =>         'integer',
+        INT2 =>         'integer',
+        INT3 =>         'integer',
+        INT4 =>         'integer',
+
+        SMALLSERIAL  => 'integer',
+        MEDIUMSERIAL => 'integer',
+        INTSERIAL    => 'integer',
+
+        TINYTEXT   =>   'varchar(255)',
+        MEDIUMTEXT =>   'varchar(4000)',
+        LONGTEXT   =>   'clob',
+
+        LONGBLOB =>     'blob',
+
+        DATETIME =>     'date',
+
+    };
+
+    $self->_adjust_schema;
+
+    return $self;
+
+} #eosub--_initialize
+#--------------------------------------------------------------------
+
+sub get_table_ddl {
+    my $self = shift;
+    my $table = shift;
+    unshift @_, $table;
+    my @ddl = $self->SUPER::get_table_ddl(@_);
+
+    my @fields = @{ $self->{abstract_schema}{$table}{FIELDS} || [] };
+    while (@fields) {
+        my $field_name = shift @fields;
+        my $field_info = shift @fields;
+        # Create triggers to deal with empty string. 
+        if ( $field_info->{TYPE} =~ /varchar|TEXT/i 
+                && $field_info->{NOTNULL} ) {
+             push (@ddl, _get_notnull_trigger_ddl($table, $field_name));
+        }
+        # Create sequences and triggers to emulate SERIAL datatypes.
+        if ( $field_info->{TYPE} =~ /SERIAL/i ) {
+            push (@ddl, _get_create_seq_ddl($table, $field_name));
+        }
+    }
+    return @ddl;
+
+} #eosub--get_table_ddl
+
+# Extend superclass method to create Oracle Text indexes if index type 
+# is FULLTEXT from schema. Returns a "create index" SQL statement.
+sub _get_create_index_ddl {
+
+    my ($self, $table_name, $index_name, $index_fields, $index_type) = @_;
+    $index_name = "idx_" . substr(md5_hex($index_name),0,20);
+    if ($index_type eq 'FULLTEXT') {
+        my $sql = "CREATE INDEX $index_name ON $table_name (" 
+                  . join(',',@$index_fields)
+                  . ") INDEXTYPE IS CTXSYS.CONTEXT "
+                  . " PARAMETERS('LEXER BZ_LEX SYNC(ON COMMIT)')" ;
+        return $sql;
+    }
+
+    return($self->SUPER::_get_create_index_ddl($table_name, $index_name, 
+                                               $index_fields, $index_type));
+
+} #eosub--_get_create_index_ddl
+
+# Oracle supports the use of FOREIGN KEY integrity constraints 
+# to define the referential integrity actions, including:
+# - Update and delete No Action (default)
+# - Delete CASCADE
+# - Delete SET NULL
+sub get_fk_ddl {
+    my ($self, $table, $column, $references) = @_;
+    return "" if !$references;
+
+    my $update    = $references->{UPDATE} || 'CASCADE';
+    my $delete    = $references->{DELETE};
+    my $to_table  = $references->{TABLE}  || confess "No table in reference";
+    my $to_column = $references->{COLUMN} || confess "No column in reference";
+    my $fk_name   = $self->_get_fk_name($table, $column, $references);
+
+    my $fk_string = "\n     CONSTRAINT $fk_name FOREIGN KEY ($column)\n"
+                    . "     REFERENCES $to_table($to_column)\n";
+   
+    $fk_string    = $fk_string . "     ON DELETE $delete" if $delete; 
+    
+    if ( $update =~ /CASCADE/i ){
+        my $tr_str = "CREATE OR REPLACE TRIGGER ". $table . "_uc"
+                     . " AFTER  UPDATE  ON ". $table
+                     . " REFERENCING "
+                     . " NEW AS NEW "
+                     . " OLD AS OLD "
+                     . " FOR EACH ROW "
+                     . " BEGIN "
+                     . "     UPDATE ". $to_table
+                     . "     SET ". $to_column . " = :NEW.". $column
+                     . "     WHERE ". $to_column . " = :OLD.". $column . ";"
+                     . " END ". $table . "_uc;";
+        my $dbh = Bugzilla->dbh; 
+        $dbh->do($tr_str);      
+    }
+
+    return $fk_string;
+}
+
+sub _get_fk_name {
+    my ($self, $table, $column, $references) = @_;
+    my $to_table  = $references->{TABLE};
+    my $to_column = $references->{COLUMN};
+    my $fk_name   = "${table}_${column}_${to_table}_${to_column}";
+    $fk_name      = "fk_" . substr(md5_hex($fk_name),0,20);
+    
+    return $fk_name;
+}
+
+sub _get_notnull_trigger_ddl {
+      my ($table, $column) = @_;
+
+      my $notnull_sql = "CREATE OR REPLACE TRIGGER "
+                        . " ${table}_${column}"
+                        . " BEFORE INSERT OR UPDATE ON ". $table
+                        . " FOR EACH ROW"
+                        . " BEGIN "
+                        . " IF :NEW.". $column ." IS NULL THEN  "
+                        . " SELECT '" . Bugzilla::DB::Oracle::EMPTY_STRING
+                        . "' INTO :NEW.". $column ." FROM DUAL; "
+                        . " END IF; "
+                        . " END ".$table.";";
+     return $notnull_sql;
+}
+
+sub _get_create_seq_ddl {
+     my ($table, $column) = @_;
+     my @ddl;
+     my $seq_name = "${table}_${column}_SEQ";
+     my $seq_sql = "CREATE SEQUENCE $seq_name "
+                   . " INCREMENT BY 1 "
+                   . " START WITH 1 "
+                   . " NOMAXVALUE "
+                   . " NOCYCLE "
+                   . " NOCACHE";
+     my $serial_sql = "CREATE OR REPLACE TRIGGER ${table}_${column}_TR "
+                    . " BEFORE INSERT ON ${table} "
+                    . " FOR EACH ROW "
+                    . " BEGIN "
+                    . "   SELECT ${seq_name}.NEXTVAL "
+                    . "   INTO :NEW.${column} FROM DUAL; "
+                    . " END;";
+    push (@ddl, $seq_sql);
+    push (@ddl, $serial_sql);
+
+    return @ddl;
+}
+
+1;