MySQL错误上触发创作与提取功能

Question

当我试图创建触发器下面给出，

CREATE TRIGGER FiscalYearTable1_bi 
BEFORE INSERT 
ON FiscalYearTable1 
FOR EACH ROW 
    IF ( 
      (EXTRACT (YEAR FROM FiscalYearTable1.start_date) != FiscalYearTable1.fiscal_year - 1) OR 
      (EXTRACT (MONTH FROM FiscalYearTable1.start_date) != 04) OR 
      (EXTRACT (DAY FROM FiscalYearTable1.start_date) != 01) 
     ) 
      SET FiscalYearTable1.fiscal_year = 1/0; 

我获得以下错误，

ERROR 1064（42000）：你有一个错误你的SQL语法;检查对应于你的MySQL服务器版本使用附近的正确语法手册“FROM FiscalYearTable1.start_date）= FiscalYearTable1.fiscal_year - 1）或（EXTRA”在1号线

我想不出是什么错误任何想法感谢

Answer 1

是这样的：？

delimiter # 

create trigger FiscalYearTable1_before_ins_trig before insert on FiscalYearTable1 
for each row 
begin 

declare y smallint unsigned default 0; 
declare m tinyint unsigned default 0; 
declare d tinyint unsigned default 0; 

    set y = year(new.start_date); 
    set m = month(new.start_date); 
    set d = day(new.start_date); 

    -- whatever logic you require... 
    if y != new.fiscal_year-1 or m != 4 or d != 1 then 
    set new.fiscal_year = null; 
    end if; 

end# 

delimiter ;