informix 在 update后报-100错

一把火

这是什么错！
出现的原因是什么呀

zhan_yl

-100    ISAM error: duplicate value for a record with unique key.

A row that was to be inserted or updated has a key value that already
exists in its index. For C-ISAM programs, a duplicate value was
presented in the last call to iswrite, isrewrite, isrewcurr, or
isaddindex. Review the program logic and the input data. For SQL
products, a duplicate key value was used in the last INSERT or UPDATE.
唯一索引上有重复值了