您不在觸發器中select;只需使用:new偽記錄的值。 Sample tables: SQL> CREATE TABLE emp_proj ( 2 empno NUMBER(4, 0) NOT NULL, 3 projno NUMBER(4, 0) NOT NULL, 4 hoursworked NUMBER(6, 2) NOT NULL, -- can't be NUMBER(4, 2) as you can't insert values => 100 5 CONSTRAINT emp_proj_empno_projno_pk PRIMARY KEY ( empno, 6 projno ) 7 );Table created.SQL> CREATE TABLE emp_proj_overtime ( 2 empno NUMBER(4, 0) NOT NULL, 3 projno NUMBER(4, 0) NOT NULL, 4 hourot NUMBER(22) NOT NULL, 5 CONSTRAINT emp_proj_overtime_empno_projno_pk PRIMARY KEY ( empno, 6 projno ) 7 );Table created. 觸發器:由于主鍵約束被定義為復合鍵,每個[empno,projno]組合只能有一行。