because this error occurs when I try to make an attribute mandatory?
org.springframework.jdbc.UncategorizedSQLException: PreparedStatementCallback; uncategorized SQLException for SQL [SELECT _cm3_attribute_modify(?::regclass,?,?,?::jsonb)]; SQL state [P0001]; error code [0]; ERROR: CM_FORBIDDEN_OPERATION: error setting notnull flag on attribute “Regleteros”.NumOfUnits: there are active cards with null values for this attribute Where: PL/pgSQL function _cm3_attribute_notnull_set(regclass,character varying,boolean) line 26 at RAISE SQL statement “SELECT _cm3_attribute_notnull_set(_class, _attr, _not_null)” PL/pgSQL function _cm3_attribute_modify(regclass,character varying,character varying,jsonb) line 39 at PERFORM; nested exception is org.postgresql.util.PSQLException: ERROR: CM_FORBIDDEN_OPERATION: error setting notnull flag on attribute “Regleteros”.NumOfUnits: there are active cards with null values for this attribute Where: PL/pgSQL function _cm3_attribute_notnull_set(regclass,character varying,boolean) line 26 at RAISE SQL statement “SELECT _cm3_attribute_notnull_set(_class, _attr, _not_null)” PL/pgSQL function _cm3_attribute_modify(regclass,character varying,character varying,jsonb) line 39 at PERFORM, caused by: org.postgresql.util.PSQLException: ERROR: CM_FORBIDDEN_OPERATION: error setting notnull flag on attribute “Regleteros”.NumOfUnits: there are active cards with null values for this attribute Where: PL/pgSQL function _cm3_attribute_notnull_set(regclass,character varying,boolean) line 26 at RAISE SQL statement “SELECT _cm3_attribute_notnull_set(_class, _attr, _not_null)” PL/pgSQL function _cm3_attribute_modify(regclass,character varying,character varying,jsonb) line 39 at PERFORM