为什么informix不让我做删库操作

[beyond_ml]

我建立了一个数据库，其中大概有160多个数据表，但我做删除库操作的时候（使用dbaccess），却出现了下面的问题，如果我先手动删除其中的几个表，操作就可以执行了。请问这是为什么？

错误提示信息：
DATABASE: Select Create Drop Exit
Drop a database.

----------------------- hhs2002 ---------------- Press CTRL-W for Help --------


//error1
215: Cannot open file for table ().
//error2
331: Cannot drop database directory.
//error3
Database Dropped


//informix:
-215

__________________________________________________________


Cannot open file for table table-name.

The database server cannot open the operating-system file or files in which the table is stored.
Check the accompanying ISAM error code for more information. Problems with operating-system file
permissions, insufficient memory, or hardware might cause this error.

-331

__________________________________________________________
Cannot drop database directory.

While the database server was executing the DROP DATABASE statement, it removed all
database-related files from the dbname.dbs directory and tried to remove the directory
itself, but an error occurred. Check the accompanying ISAM error code for more detailed
information on the cause. The most likely cause is that you or another user created
nondatabase files in the same directory, and the directory cannot be removed because
it is not yet empty.

[beyond_ml]

难道没有人知道么？

[愉快的登山者]

是否存在关联约束。