c# - 获取错误为 "input array is longer than the number of columns in this table"

Question

代码。

Public Function comb1(ByVal SName As String) As DataTable

        Dim dt As New DataTable
        cmd = New SqlCommand("Select Distinct RName from tb_RS_New", con)
        dr2 = cmd.ExecuteReader
        While (dr2.Read())
            dt.Rows.Add(dr2("RName"))
        End While
        Return dt

End Function

加载页面时，抛出错误“输入数组长于该表中的列数”

我的代码有什么问题。

需要帮助

Answer 1

您需要先向该数据表添加列:

Dim dt As New DataTable
dt.Columns.Add("RName", GetType(String))

此外，我对您代码中的 con、cmd 和 dr2 变量了解不多，但我强烈建议您处理他们正确地:

Dim dt As New DataTable
dt.Columns.Add("RName", GetType(String))

Using con As New SqlConnection("connection string to the database")
    Using cmd = con.CreateCommand()
        con.Open()
        cmd.CommandText = "Select Distinct RName from tb_RS_New"
        Using dr = cmd.ExecuteReader()
            While (dr.Read())
                dt.Rows.Add(dr("RName"))
            End While
        End Using
    End Using
End Using