我被它折磨了一下午!
sqlstrMajor = dtcmbQMajor.Text 'datacombo
major_name = sqlstrMajor
'dtMain、dtSec都是ADOdata控件
dtMain.RecordSource = "select major_ID from major where major_name='" + major_name + "'"
dtMain.Refresh
major_ID = dtMain.Recordset("major_ID")
这段代码如果不设断点,有时候三sqlstrMajor的值无法传进来,然后后边查询结果就是空的。
dtSec.RecordSource = "select class_name from class where major_ID='" + major_ID + "'"
dtSec.Refresh
dtcmbQClass.ListField = "class_name"
这段代码在refresh时失败,说“至少一个参数没有被指定值”。dtSec是后加的,有关系吗?