Update V7_1__NewExperimentResultFormat.sql

Created by: KFilippopolitis

Cherry pick updated migration script 7.1

src/main/resources/db/migration/V7_1__NewExperimentResultFormat.sql

-UPDATE experiment SET result = result::json #>>'{0,result}' WHERE (algorithm::json->>'type') <> 'workflow';
\ No newline at end of file
+CREATE OR REPLACE FUNCTION ISJSON(p_json text)
+    RETURNS boolean
+AS
+$$
+BEGIN
+    RETURN (p_json::json is not null);
+EXCEPTION
+    WHEN others THEN
+        RETURN false;
+END;
+$$
+language plpgsql
+immutable;
+UPDATE experiment SET result = result::json #>>'{0,result}' WHERE (algorithm::json->>'type') <> 'workflow' and ISJSON(result);
+UPDATE experiment SET result = '', status = 'error' WHERE NOT ISJSON(result);