代码操作如下，字段都是字符类型的

明明都是字符串，但是却弹出从字符串“gsmc”到类型“Double”的转换无效。请问什么问题啊

Dim Texts() As String = {"gsmc","gstel","gsmail","gslxdz"}
Dim ct() As String ={"TextBox1","TextBox2","TextBox3","TextBox4"}
Dim cmd As New SQLCommand
cmd.C

For  i As Integer  = 0 To Texts.Length-1
    cmd.CommandText = "Sele ct     [jbszbm] from {ck_sz_ckjbsz} where jbszbm= \'" & Texts(i) & "\' "
    If cmd.ExecuteScalar()>0 Then
        cmd.CommandText = "UPDA TE     [ck_sz_ckjbsz] SET jbszzd = \'" & e.Form.Controls(ct(i)).value & "\' WHERE [jbszbm] = \'" & Texts(i) & "\'"
        cmd.ExecuteNonQuery()
    Else
        cmd.CommandText = "Ins ert Into [ck_sz_ckjbsz] (jbszbm,jbszzd) Values(\'" & Texts(i) & "\',\'" &  e.Form.Controls(ct(i)).value & "\')"
        cmd.ExecuteNonQuery()
    End If
Next

这句代码有问题， 返回的值应该是字符，不可能和0比较

If cmd.ExecuteScalar() <> Nothing Then

可以了谢谢