Correctly compare numeric field values

modules/store/src/main/resources/db/migration/mariadb/V1.21.0__cast_function.sql

@@ -0,0 +1,5 @@
+-- Create a function to cast to a numeric, if an error occurs return null
+-- Could not get it working with decimal type, so using double
+create or replace function CAST_TO_NUMERIC (s char(255))
+returns double deterministic
+return cast(s as double);