From: Sandro Santilli <strk@kbt.io>
Date: Thu, 6 Sep 2018 22:21:03 +0000 (+0000)
Subject: Do not DROP CASCADE types which are still used in columns
X-Git-Tag: 3.0.0alpha1~464
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0a1c061a56dafeda85716996aa2c6d784496ba53;p=postgis

Do not DROP CASCADE types which are still used in columns

git-svn-id: http://svn.osgeo.org/postgis/trunk@16719 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/utils/create_undef.pl b/utils/create_undef.pl
index 3795bb53d..13d388989 100755
--- a/utils/create_undef.pl
+++ b/utils/create_undef.pl
@@ -246,10 +246,44 @@ foreach my $fn (@funcs)
 }
 
 
-print "-- Drop all types.\n";
+print "-- Drop all types if unused in column types.\n";
+my $quotedtypelist = join ',', map { "'$_'" } @types;
 foreach my $type (@types)
 {
-	print "DROP TYPE IF EXISTS $type CASCADE;\n";
+	print <<EOF;
+DO \$\$
+DECLARE
+	rec RECORD;
+BEGIN
+	FOR rec IN
+		SELECT n.nspname, c.relname, a.attname, t.typname
+		FROM pg_attribute a
+		JOIN pg_class c ON a.attrelid = c.oid
+		JOIN pg_namespace n ON c.relnamespace = n.oid
+		JOIN pg_type t ON a.atttypid = t.oid
+		WHERE t.typname = '$type'
+		  AND NOT (
+				-- we exclude coplexes defined as types
+				-- by our own extension
+				c.relkind = 'c'
+				AND
+				c.relname in ( $quotedtypelist )
+			)
+	LOOP
+		RAISE EXCEPTION
+		  'Column "%" of table "%"."%" '
+		  'depends on type "%", drop it first',
+		  rec.attname, rec.nspname, rec.relname, rec.typname;
+	END LOOP;
+END;
+\$\$;
+-- NOTE: CASCADE is still needed for chicken-egg problem
+--       of input function depending on type and type
+--       depending on function
+DROP TYPE IF EXISTS $type CASCADE;
+
+EOF
+
 }
 
 print "-- Drop all functions needed for types definition.\n";