Allow Admin users to Insert/Update/Delete on certain table

Allow Admin users to Insert/Update/Delete on certain table

How to create a trigger in oracle which will restrict insertion and update queries on a table based on a condition

CREATE OR REPLACE TRIGGER SIEBEL.BLOCK_NON_ADMIN_ACCESS

BEFORE DELETE OR INSERT OR UPDATE

ON SIEBEL.CX_ERROR_LOG

REFERENCING NEW AS NEW OLD AS OLD

FOR EACH ROW

begin

    IF sys_context('USERENV','SESSION_USER') NOT IN ('SADMIN', 'EIMUSER') THEN

        RAISE_APPLICATION_ERROR(-20000, 'You are not allowed to update table CX_ERROR_LOG. Please contact Application Support.');

    END IF;

END;