MSSQL数据源，下面代码怎么取不到YYYYMM这样的年月？
Dim qj As WinForm.ComboBox = e.Form.Controls("ComboBox1")
Dim cmd As New SQ1LCommand
Dim dt2 As DataTable
cmd.Conn1ectionName = "mysql"
cmd.Com1mandText = "Sel1ect [_Identify],CAST(Fyear AS NVARCHAR(4)) + RIGHT('0' + CAST(FPeriod AS NVARCHAR(2)), 2) as 年月 From {My_GLVch} where [FSerialNum] Is NULL"
dt2 = cmd.Exe1cuteReader()
qj.ComboList = dt2.sqlGetComboListString("年月")