主题：[讨论]关于在select如何中引用变量的问题。

有这样几行代码是可以执行的：

Dim q As new QueryBuilder
q.TableName = "会计凭证查询"
q.C
dim s as string
    s =  "select * from [z_tabdqpz] where sszt = "& e.Form.Controls("账套编号").Value &"and pzrqn = "& e.Form.Controls("账套年度").Value
    s = s & "union all select * from [z_tabxqpz] where sszt = "& e.Form.Controls("账套编号").Value &"and pzrqn = "& e.Form.Controls("账套年度").Value
    s = s & "union all select * from [z_tablqpz] where sszt = "& e.Form.Controls("账套编号").Value &"and pzrqn = "& e.Form.Controls("账套年度").Value
    s = s & "order by pzrqn,pzrqy,pzlx,pzdm,flxh"
q.SelectString = s
q.Build

但是我用定义的变量写入select中，就不能执行了：

Dim ztbh As WinForm.TextBox = e.Form.Controls("账套编号").Value

Dim q As new QueryBuilder
q.TableName = "会计凭证查询"
q.C
dim s as string
    s =  "select * from [z_tabdqpz] where sszt = "& ztbh &"and pzrqn = "& ztnd

    s = s & "union all select * from [z_tabxqpz] where sszt = "& ztbh &"and pzrqn = ztnd

    s = s & "union all select * from [z_tablqpz] where sszt = "& ztbh &"and pzrqn = ztnd

    s = s & "order by pzrqn,pzrqy,pzlx,pzdm,flxh"
q.SelectString = s
q.Build

规则本来就是这样的吗？