代码报错 data truncated

以上，代码报错，烦请老师帮忙查下原因，谢谢。

附：

UPDATE t_emp e  LEFT JOIN t_dept d ON e.deptno = d.deptno

LEFT JOIN (SELECT deptno, avg(sal) AS avgsal FROM t_emp GROUP BY deptno) t

ON e.deptno = t.deptno

SET e.sal= (

case

when d.dname = "SALES" AND DATEDIFF(NOW(),e.hiredate)/365 >= 20 

then e.sal*1.1

when d.dname = "SALES" AND DATEDIFF(NOW(),e.hiredate)/365 < 20 

then e.sal*1.05

when d.dname = "ACCOUNTING" 

then e.sal +300

when d.dname = "RESEARCH" AND e.sal <t.avgsal 

then e.sal +200

when e.deptno IS NULL then e.sal +100

ELSE e.sal

end

);