为什么我会收到 "No value given for one or more required parameters." Vb.net 的错误消息

Question

Dim SqlQueryActivity As String = "SELECT * FROM tblActivities WHERE Activity ='" & ActivityCombo.Text & "'AND Sub-Activity = '" & SubActivityCombo.Text & "'"
    Dim DataAdapterActivities As OleDbDataAdapter = New OleDbDataAdapter(SqlQueryActivity, conn)
    Dim DataSetActivities As DataSet = New DataSet
    DataAdapterActivities.Fill(DataSetActivities, "ActivitiesData")
    Dim DataTableActivities As DataTable = DataSetActivities.Tables("ActivitiesData")

当运行代码时，我得到了提到的错误，指向填充了 DataAdapterActivities 的第 4 行。我已经检查过组合框中的内容是否与数据库中的记录相匹配。此 sql 语句在插入语句之前运行以检索适当的详细信息。我试图了解我是否需要在某个地方单独定义 activitiesdata ，或者它是什么正在被填充。我刚刚打开了连接。

Answer 1

您应该将查询记录在一个文件中，然后直接在数据库中尝试。

这是您的查询

SELECT * FROM tblActivities WHERE Activity ='?'AND Sub-Activity = '?'

Sub 和 Activity 之间有一个减号。您的数据库会认为您想要减去列 Sub 和 Activity，我认为您没有，因为您收到错误。

我建议您重命名 table

中的列（删除减号或用其他内容替换）

SELECT * FROM tblActivities WHERE Activity ='?'AND SubActivity = '?'

或者在查询中使用括号

SELECT * FROM tblActivities WHERE Activity ='?'AND [Sub-Activity] = '?'

为什么我会收到 "No value given for one or more required parameters." Vb.net 的错误消息

Why do I get the error saying "No value given for one or more required parameters." Vb.net

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