主题：错误提示

请问如下提示是什么意思：
此主题相关图片如下：未命名.gif


此主题相关图片如下：未命名1.gif

是不是下面代码错误：

Dim Sum As Double = Tables("生产工序").Compute("Sum(工艺工时_天数)","[图号] = '" & dr("图号") & "' And [派工单号] = '" & dr("派工单号") & "' And [状态]= '执行'  And [工序_序号] <= " & dr("工序_序号"))
Dim Sum1 As Double = Tables("生产工序").Compute("Sum(工艺工时_天数)","[图号] = '" & dr("图号") & "' And [派工单号] = '" & dr("派工单号") & "' And [状态]= '执行' And [工序_序号] >= " & dr("工序_序号"))

改成如下行吗？（工序_序号列是字符型列）
Dim Sum As Double = Tables("生产工序").Compute("Sum(工艺工时_天数)","[图号] = '" & dr("图号") & "' And [派工单号] = '" & dr("派工单号") & "' And [状态]= '执行'  And [工序_序号] <= '" & dr("工序_序号")& "'")
 Dim Sum1 As Double = Tables("生产工序").Compute("Sum(工艺工时_天数)","[图号] = '" & dr("图号") & "' And [派工单号] = '" & dr("派工单号") & "' And [状态]= '执行' And [工序_序号] >= '" & dr("工序_序号")& "'")

我已把数据类型改成数值型了，我再试试看，谢谢