Fix syntax error when changing the event type for the existing rule. It is a regression of #5115.

Fixes #5215

docs/en_US/release_notes_4_19.rst

@@ -29,4 +29,5 @@ Bug fixes
 | `Issue #5077 <https://redmine.postgresql.org/issues/5077>`_ -  Changed background pattern for geometry viewer to use #fff for all themes.
 | `Issue #5107 <https://redmine.postgresql.org/issues/5107>`_ -  Set proper focus on tab navigation for file manager dialog.
 | `Issue #5115 <https://redmine.postgresql.org/issues/5115>`_ -  Fix an issue where command and statements were parsed incorrectly for Rules.
-| `Issue #5184 <https://redmine.postgresql.org/issues/5184>`_ -  Fixed Firefox monospaced issue by updating the font to the latest version.
+| `Issue #5184 <https://redmine.postgresql.org/issues/5184>`_ -  Fixed Firefox monospaced issue by updating the font to the latest version.
+| `Issue #5215 <https://redmine.postgresql.org/issues/5215>`_ -  Fix syntax error when changing the event type for the existing rule.

web/pgadmin/browser/server_groups/servers/databases/schemas/tables/rules/tests/default/alter_insert_event_rule_nothing.sql

@@ -0,0 +1,10 @@
+-- Rule: "test_insert_rule1_$%{}[]()&*^!@""'`\/#" ON public.test_emp_rule
+
+-- DROP Rule "test_insert_rule1_$%{}[]()&*^!@""'`\/#" ON public.test_emp_rule;
+
+CREATE OR REPLACE RULE "test_insert_rule1_$%{}[]()&*^!@""'`\/#" AS
+    ON INSERT TO public.test_emp_rule
+    WHERE (new.salary > 8000)
+    DO INSTEAD NOTHING;
+
+COMMENT ON RULE "test_insert_rule1_$%{}[]()&*^!@""'`\/#" ON public.test_emp_rule IS 'This is a insert rule';

web/pgadmin/browser/server_groups/servers/databases/schemas/tables/rules/tests/default/alter_insert_event_rule_nothing_msql.sql

@@ -0,0 +1,4 @@
+CREATE OR REPLACE RULE "test_insert_rule1_$%{}[]()&*^!@""'`\/#" AS
+    ON INSERT TO public.test_emp_rule
+    WHERE (new.salary > 8000)
+    DO INSTEAD NOTHING;

web/pgadmin/browser/server_groups/servers/databases/schemas/tables/rules/tests/default/alter_insert_event_rule_nothing_update.sql

@@ -0,0 +1,10 @@
+-- Rule: "test_insert_rule1_$%{}[]()&*^!@""'`\/#" ON public.test_emp_rule
+
+-- DROP Rule "test_insert_rule1_$%{}[]()&*^!@""'`\/#" ON public.test_emp_rule;
+
+CREATE OR REPLACE RULE "test_insert_rule1_$%{}[]()&*^!@""'`\/#" AS
+    ON UPDATE TO public.test_emp_rule
+    WHERE (new.salary > 8000)
+    DO INSTEAD NOTHING;
+
+COMMENT ON RULE "test_insert_rule1_$%{}[]()&*^!@""'`\/#" ON public.test_emp_rule IS 'This is a insert rule';

web/pgadmin/browser/server_groups/servers/databases/schemas/tables/rules/tests/default/alter_insert_event_rule_nothing_update_msql.sql

@@ -0,0 +1,4 @@
+CREATE OR REPLACE RULE "test_insert_rule1_$%{}[]()&*^!@""'`\/#" AS
+    ON UPDATE TO public.test_emp_rule
+    WHERE (new.salary > 8000)
+    DO INSTEAD NOTHING;

web/pgadmin/browser/server_groups/servers/databases/schemas/tables/rules/tests/default/test.json

@@ -33,7 +33,7 @@
         "name": "test_insert_rule_$%{}[]()&*^!@\"'`\\/#",
         "schema": "public",
         "view": "test_emp_rule",
-        "event": "Insert",
+        "event": "INSERT",
         "condition": "new.salary > 5000",
         "statements": "UPDATE test_emp_rule SET salary = 5000\n  WHERE test_emp_rule.emp_id = new.emp_id"
       },
@@ -49,7 +49,7 @@
         "name": "test_insert_rule1_$%{}[]()&*^!@\"'`\\/#",
         "schema": "public",
         "view": "test_emp_rule",
-        "event": "Insert",
+        "event": "INSERT",
         "do_instead": true,
         "comment": "This is a insert rule",
         "condition": "new.salary > 8000",
@@ -59,7 +59,7 @@
       "expected_msql_file": "alter_insert_event_rule_msql.sql"
     }, {
       "type": "alter",
-      "name": "Alter Rule for insert event with complex commands",
+      "name": "Alter Rule insert to update event with complex commands",
       "endpoint": "NODE-rule.obj_id",
       "sql_endpoint": "NODE-rule.sql_id",
       "msql_endpoint": "NODE-rule.msql_id",
@@ -68,6 +68,28 @@
       },
       "expected_sql_file": "alter_insert_event_rule_complex.sql",
       "expected_msql_file": "alter_insert_event_rule_complex_msql.sql"
+    }, {
+      "type": "alter",
+      "name": "Alter Rule for insert event to statements NOTHING",
+      "endpoint": "NODE-rule.obj_id",
+      "sql_endpoint": "NODE-rule.sql_id",
+      "msql_endpoint": "NODE-rule.msql_id",
+      "data": {
+        "statements": "NOTHING"
+      },
+      "expected_sql_file": "alter_insert_event_rule_nothing.sql",
+      "expected_msql_file": "alter_insert_event_rule_nothing_msql.sql"
+    }, {
+      "type": "alter",
+      "name": "Alter Rule for insert with NOTHING to Update",
+      "endpoint": "NODE-rule.obj_id",
+      "sql_endpoint": "NODE-rule.sql_id",
+      "msql_endpoint": "NODE-rule.msql_id",
+      "data": {
+        "event": "UPDATE"
+      },
+      "expected_sql_file": "alter_insert_event_rule_nothing_update.sql",
+      "expected_msql_file": "alter_insert_event_rule_nothing_update_msql.sql"
     }, {
       "type": "delete",
       "name": "Drop Rule",
@@ -85,7 +107,7 @@
         "name": "test_update_rule_$%{}[]()&*^!@\"'`\\/#",
         "schema": "public",
         "view": "test_emp_rule",
-        "event": "Update",
+        "event": "UPDATE",
         "condition": "old.name = 'Joe'",
         "statements": "UPDATE test_emp_rule SET salary = new.salary\n  WHERE test_emp_rule.name = 'Sam'"
       },
@@ -101,7 +123,7 @@
         "name": "test_update_rule1_$%{}[]()&*^!@\"'`\\/#",
         "schema": "public",
         "view": "test_emp_rule",
-        "event": "Update",
+        "event": "UPDATE",
         "do_instead": true,
         "comment": "This is a update rule",
         "condition": "old.name = 'Sam'",

web/pgadmin/browser/server_groups/servers/databases/schemas/tables/templates/rules/sql/update.sql

@@ -8,7 +8,7 @@
 ALTER RULE {{ conn|qtIdent(o_data.name) }} ON {{ conn|qtIdent(o_data.schema, o_data.view) }} RENAME TO {{ conn|qtIdent(data.name) }};
 
 {% endif %}
-{% if data.event or data.do_instead is defined or data.condition is defined or data.statements is defined %}
+{% if data.event is defined or data.do_instead is defined or data.condition is defined or data.statements is defined %}
 CREATE OR REPLACE RULE {{ conn|qtIdent(rule_name) }} AS
     ON {% if data.event and data.event != o_data.event %}{{ data.event|upper }}{% else %}{{ o_data.event|upper }}{% endif %}
  TO {{ conn|qtIdent(o_data.schema, o_data.view) }}
@@ -18,16 +18,17 @@ CREATE OR REPLACE RULE {{ conn|qtIdent(rule_name) }} AS
     WHERE ({{ o_data.condition }})
 {% endif %}
     DO{% if (('do_instead' not in data and o_data.do_instead in ['true', True]) or (data.do_instead in ['true', True])) %}{{ ' INSTEAD' }}{% endif %}
-{% if data.statements and data.statements != o_data.statements and data.statements.strip() in ['', 'NOTHING']%}
+{% if data.statements is defined %}
+{% if data.statements.strip() in ['', 'NOTHING'] %}
  NOTHING;
-{% elif data.statements and data.statements != o_data.statements %}
+{% else %}
 
 ({{ data.statements.rstrip(';') }});
-{% elif data.statements is not defined and o_data.statements %}
+{% endif %}
-
+{% elif o_data.statements.strip() in ['', 'NOTHING'] %}
-({{ o_data.statements.rstrip(';') }});
-{% else %}
  NOTHING;
+{% else %}
+({{ o_data.statements.rstrip(';') }});
 {% endif %}
 
 {% endif %}