主题：compute中条件方括号问题

使用compute发现帮助里面有两种情况，条件有一种带方括号，另一种不带。
有什么区别？
示例二

计算产品PD01的销售数量：

Dim Total As Long
Total = DataTables("订单").Compute("Sum(数量)", "产品 = 'PD01'")
Output.Show(Total)

示例三

计算每个客户的订购数量：

Dim Customers As List(Of String)
Dim Total As Integer
Customers = DataTables("订单").GetUniqueValues("", "客户")
For Each Customer As String In Customers
    Total = DataTables("订单").Compute("Sum(数量)", "[客户] = '" & Customer & "'")
    Output.Show(Customer & ":" & Total)
Next