#33: Fix trigger if table contains column with non-equality type for ignore_unchanged_values=false

README.md

@@ -110,6 +110,8 @@ Should return something similar to:
 
 ### Ignore updates without actual change
 
+**NOTE: This feature does not work for tables with columns with types that does not support equality operator (e.g. PostGIS types, JSON types, etc.).**
+
 By default this extension creates a record in the history table for every update that occurs in the versioned table, regardless of any change actually happening.
 
 We added a fourth paramater to the trigger to change this behaviour and only record updates that result in an actual change.

test/expected/non_equality_types.out

@@ -0,0 +1,7 @@
+SET client_min_messages TO error
+CREATE TABLE non_equality_types (json json, sys_period tstzrange)
+CREATE TRIGGER versioning_trigger
+BEFORE INSERT OR UPDATE OR DELETE ON non_equality_types
+FOR EACH ROW EXECUTE PROCEDURE versioning('sys_period', 'non_equality_types', false)
+INSERT INTO non_equality_types VALUES ('{"a":1}'::json)
+UPDATE non_equality_types SET json = '{"a":2}'::json WHERE 1=1

test/expected/non_equality_types_unchanged_values.out

@@ -0,0 +1,9 @@
+SET client_min_messages TO error
+CREATE TABLE non_equality_types_unchanged_values (json json, sys_period tstzrange)
+CREATE TRIGGER versioning_trigger
+BEFORE INSERT OR UPDATE OR DELETE ON non_equality_types_unchanged_values
+FOR EACH ROW EXECUTE PROCEDURE versioning('sys_period', 'non_equality_types_unchanged_values', false, true)
+INSERT INTO non_equality_types_unchanged_values VALUES ('{"a":1}'::json)
+UPDATE non_equality_types_unchanged_values SET json = '{"a":2}'::json WHERE 1=1
+ERROR:  could not identify an equality operator for type json
+CONTEXT:  PL/pgSQL function versioning() line 39 at IF

test/runTest.sh

@@ -9,7 +9,8 @@ TESTS="
   no_history_table no_history_system_period no_system_period
   invalid_system_period_values invalid_system_period invalid_types
   versioning upper_case structure combinations
-  different_schema unchanged_values unchanged_version_values"
+  different_schema unchanged_values unchanged_version_values
+  non_equality_types non_equality_types_unchanged_values"
 
 for name in $TESTS; do
   echo ""
@@ -20,4 +21,4 @@ for name in $TESTS; do
 done
 
 
-psql -q -c "drop database temporal_tables_test;"
+psql -q -c "drop database temporal_tables_test;"

test/runTestNochecks.sh

@@ -7,7 +7,9 @@ mkdir -p test/result
 
 TESTS="
   versioning upper_case structure combinations different_schema unchanged_values
-  unchanged_version_values"
+  non_equality_types non_equality_types_unchanged_values
+  unchanged_version_values
+  "
 
 for name in $TESTS; do
   echo ""
@@ -18,4 +20,4 @@ for name in $TESTS; do
 done
 
 
-psql -q -c "drop database temporal_tables_test;"
+psql -q -c "drop database temporal_tables_test;"

test/sql/non_equality_types.sql

@@ -0,0 +1,11 @@
+SET client_min_messages TO error;
+
+CREATE TABLE non_equality_types (json json, sys_period tstzrange);
+
+CREATE TRIGGER versioning_trigger
+BEFORE INSERT OR UPDATE OR DELETE ON non_equality_types
+FOR EACH ROW EXECUTE PROCEDURE versioning('sys_period', 'non_equality_types', false);
+
+INSERT INTO non_equality_types VALUES ('{"a":1}'::json);
+
+UPDATE non_equality_types SET json = '{"a":2}'::json WHERE 1=1;

test/sql/non_equality_types_unchanged_values.sql

@@ -0,0 +1,11 @@
+SET client_min_messages TO error;
+
+CREATE TABLE non_equality_types_unchanged_values (json json, sys_period tstzrange);
+
+CREATE TRIGGER versioning_trigger
+BEFORE INSERT OR UPDATE OR DELETE ON non_equality_types_unchanged_values
+FOR EACH ROW EXECUTE PROCEDURE versioning('sys_period', 'non_equality_types_unchanged_values', false, true);
+
+INSERT INTO non_equality_types_unchanged_values VALUES ('{"a":1}'::json);
+
+UPDATE non_equality_types_unchanged_values SET json = '{"a":2}'::json WHERE 1=1;

versioning_function.sql

@@ -38,6 +38,12 @@ BEGIN
   history_table := TG_ARGV[1];
   ignore_unchanged_values := TG_ARGV[3];
 
+  IF ignore_unchanged_values AND TG_OP = 'UPDATE' THEN
+    IF NEW IS NOT DISTINCT FROM OLD THEN
+      RETURN OLD;
+    END IF;
+  END IF;
+
   -- check if sys_period exists on original table
   SELECT atttypid, attndims INTO holder FROM pg_attribute WHERE attrelid = TG_RELID AND attname = sys_period AND NOT attisdropped;
   IF NOT FOUND THEN

versioning_function_nochecks.sql

@@ -19,6 +19,11 @@ BEGIN
   history_table := TG_ARGV[1];
   ignore_unchanged_values := TG_ARGV[3];
 
+  IF ignore_unchanged_values AND TG_OP = 'UPDATE' THEN
+    IF NEW IS NOT DISTINCT FROM OLD THEN
+      RETURN OLD;
+    END IF;
+  END IF;
 
   IF TG_OP = 'UPDATE' OR TG_OP = 'DELETE' THEN
     -- Ignore rows already modified in the current transaction
@@ -88,4 +93,4 @@ BEGIN
 
   RETURN OLD;
 END;
-$$ LANGUAGE plpgsql;
+$$ LANGUAGE plpgsql;