Merge branch 'dev' into f-versioning

CHANGELOG.md

-# Changelog
+# Changelog #
+
 All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
-## [Unreleased]
+## [Unreleased] ##
 
-### Added
+### Added ###
 
-### Changed
+### Changed ###
 
-### Deprecated
+### Deprecated ###
 
 * Table `transaction_log` is deprecated. The functionality is being replaced by the `transactions` table.
 
-### Fixed
+### Fixed ###
 
+- Fixed several bugs when an Entity inherits from itself (#18, caosdb-server #85).
+>>>>>>> dev

procedures/insertIsaCache.sql

@@ -47,6 +47,7 @@ insert_is_a_proc: BEGIN
         -- Any additional entries would be redundant.
         LEAVE insert_is_a_proc;
     END IF;
+    -- Note: also for the next insertions, ignore existing lines with p == c
 
     -- Insert ancestors older than parents:
     -- for each supertype of p
@@ -60,7 +61,7 @@ insert_is_a_proc: BEGIN
            p,                            -- New parent (directly)
            concat(p, ">", i.rpath))      -- Else "p>super.rpath"
             AS rpath
-        FROM isa_cache AS i WHERE i.child = p;  -- Select rows with supertype
+        FROM isa_cache AS i WHERE i.child = p AND i.child != i.parent;  -- Select rows with supertype
 
     -- Propagate to descendants:
     -- for each subtype of c: insert each supertype of p
@@ -78,7 +79,7 @@ insert_is_a_proc: BEGIN
             AS rpath
         FROM
             isa_cache as l INNER JOIN isa_cache as r
-            ON (l.parent = c AND c = r.child); -- Left: descendants of c, right: ancestors
+            ON (l.parent = c AND c = r.child AND l.child != l.parent); -- Left: descendants of c, right: ancestors
 
 END;
 //