sql触发器过滤某些数据

使用触发器过滤某些特定的数据（pg数据库）

CREATE TABLE COMPANY(
   ID INT PRIMARY KEY     NOT NULL,
   NAME           TEXT    NOT NULL,
   AGE            INT     NOT NULL,
   ADDRESS        CHAR(50),
   SALARY         REAL
);  

--建立触发器
CREATE TRIGGER example_trigger before INSERT ON COMPANY
FOR EACH ROW EXECUTE PROCEDURE auditlogfunc(); 
-- 数据处理函数
CREATE OR REPLACE FUNCTION auditlogfunc() RETURNS TRIGGER AS $example_table$
    BEGIN
        if(new.ID<10)
    THEN RETURN NEW;
    else
     return null;
    end IF;
    END;
$example_table$ LANGUAGE plpgsql; 
--- test
insert into COMPANY values(6,'23',3,'333',null),(7,'23',3,'333',null),(50,'23',3,'333',null),(60,'23',3,'333',null),(8,'23',3,'333',null)
select * from COMPANY
delete from COMPANY