support MSSQL 2000 again, optimization for MSSQL

multischema support broke compatibility with SQL Server 2000 in 0.07011,
because system tables were used to find identity columns, and system
tables changed between 2000 and 2005.

We now check the SQL Server version and use a different query for 2000
and later versions.

Also optimize columns_info_for to use one query for the whole table,
instead of doing two separate queries for each column.

diff --git a/Changes b/Changes
index 8483806..d7bae34 100644 (file)
--- a/Changes
+++ b/Changes
@@ -1,5 +1,7 @@
 Revision history for Perl extension DBIx::Class::Schema::Loader
 
+        - support SQL Server 2000 again (broken in 0.07011)
+
 0.07024  2012-05-08 15:35:16
         - work around broken keyseq in DBD::Pg foreign_key_info (RT#77062)
 

diff --git a/lib/DBIx/Class/Schema/Loader/DBI/MSSQL.pm b/lib/DBIx/Class/Schema/Loader/DBI/MSSQL.pm
index b3dc834..0ab2bc7 100644 (file)
--- a/lib/DBIx/Class/Schema/Loader/DBI/MSSQL.pm
+++ b/lib/DBIx/Class/Schema/Loader/DBI/MSSQL.pm
@@ -351,20 +351,43 @@ sub _columns_info_for {
 
     my $result = $self->next::method(@_);
 
-    while (my ($col, $info) = each %$result) {
-# get type info
-        my ($char_max_length, $data_type, $datetime_precision, $default) =
-            $self->dbh->selectrow_array(<<"EOF");
-SELECT character_maximum_length, data_type, datetime_precision, column_default
-FROM [$db].INFORMATION_SCHEMA.COLUMNS
-WHERE table_name = @{[ $self->dbh->quote($table->name) ]}
-    AND table_schema = @{[ $self->dbh->quote($table->schema) ]}
-    AND @{[ $self->preserve_case ?
-        "column_name = @{[ $self->dbh->quote($col) ]}"
-        :
-        "lower(column_name) = @{[ $self->dbh->quote(lc $col) ]}" ]}
+    # SQL Server: Ancient as time itself, but still out in the wild
+    my $is_2k = $self->schema->storage->_server_info->{normalized_dbms_version} < 9;
+    
+    # get type info (and identity)
+    my $rows = $self->dbh->selectall_arrayref($is_2k ? <<"EOF2K" : <<"EOF");
+SELECT c.column_name, c.character_maximum_length, c.data_type, c.datetime_precision, c.column_default, (sc.status & 0x80) is_identity
+FROM [$db].INFORMATION_SCHEMA.COLUMNS c
+JOIN [$db].dbo.sysusers ss ON
+    c.table_schema = ss.name
+JOIN [$db].dbo.sysobjects so ON
+    c.table_name = so.name
+    AND so.uid = ss.uid
+JOIN [$db].dbo.syscolumns sc ON
+    c.column_name = sc.name
+    AND sc.id = so.Id
+WHERE c.table_schema = @{[ $self->dbh->quote($table->schema) ]}
+    AND c.table_name = @{[ $self->dbh->quote($table->name) ]}
+EOF2K
+SELECT c.column_name, c.character_maximum_length, c.data_type, c.datetime_precision, c.column_default, sc.is_identity
+FROM [$db].INFORMATION_SCHEMA.COLUMNS c
+JOIN [$db].sys.schemas ss ON
+    c.table_schema = ss.name
+JOIN [$db].sys.objects so ON
+      c.table_name   = so.name
+    AND so.schema_id = ss.schema_id
+JOIN [$db].sys.columns sc ON
+    c.column_name = sc.name
+    AND sc.object_id = so.object_id
+WHERE c.table_schema = @{[ $self->dbh->quote($table->schema) ]}
+    AND c.table_name = @{[ $self->dbh->quote($table->name) ]}
 EOF
 
+    foreach my $row (@$rows) {
+        my ($col, $char_max_length, $data_type, $datetime_precision, $default, $is_identity) = @$row;
+        $col = lc $col unless $self->preserve_case;
+        my $info = $result->{$col} || next;
+
         $info->{data_type} = $data_type;
 
         if (defined $char_max_length) {
@@ -372,31 +395,13 @@ EOF
             $info->{size} = 0 if $char_max_length < 0;
         }
 
-# find identities
-        my ($is_identity) = $self->dbh->selectrow_array(<<"EOF");
-SELECT is_identity
-FROM [$db].sys.columns
-WHERE object_id = (
-    SELECT object_id
-    FROM [$db].sys.objects
-    WHERE name = @{[ $self->dbh->quote($table->name) ]}
-        AND schema_id = (
-            SELECT schema_id
-            FROM [$db].sys.schemas
-            WHERE name = @{[ $self->dbh->quote($table->schema) ]}
-        )
-) AND @{[ $self->preserve_case ?
-    "name = @{[ $self->dbh->quote($col) ]}"
-    :
-    "lower(name) = @{[ $self->dbh->quote(lc $col) ]}" ]}
-EOF
         if ($is_identity) {
             $info->{is_auto_increment} = 1;
             $info->{data_type} =~ s/\s*identity//i;
             delete $info->{size};
         }
 
-# fix types
+        # fix types
         if ($data_type eq 'int') {
             $info->{data_type} = 'integer';
         }