增加表字段时提示无效的临时表操作

*-- tcAls - 要修改结构的临时表别名
*-- tcDef - 要添加的字段定义: 字段名,类型,长度,小数位,允许空值(0 or 1)
Function FieldAdd(tcAls, tcDef)
    Local nOldArea, cTemp, ii, jj, kk
    Local cFldName, cFldType, cFldLen, cFldDec, lAllowNull
    Local array aOld[1], aNew[1]
    m.nOldArea = Select(0)
   
    m.cFldName = GetWordNum(m.tcDef, 1, ',')
    m.cFldType = GetWordNum(m.tcDef, 2, ',')
    m.cFldLen = Cast(GetWordNum(m.tcDef, 3, ',') as I)
    m.cFldDec = Cast(GetWordNum(m.tcDef, 4, ',') as I)
    m.lAllowNull = Cast(Cast(GetWordNum(m.tcDef, 5, ',') as I) as L)
   
    m.ii = AFields(m.aOld, m.tcAls)
    If Ascan(m.aOld, m.cFldName, 1, -1, 1, 1+2+4) > 0
        *-- 字段已经存在
    Else
        m.ii = m.ii + 1
        m.jj = Alen(m.aOld, 2)
        Dimension aOld[m.ii, m.jj]
        m.aOld[m.ii, 1] = m.cFldName
        m.aOld[m.ii, 2] = m.cFldType
        m.aOld[m.ii, 3] = m.cFldLen
        m.aOld[m.ii, 4] = m.cFldDec
        m.aOld[m.ii, 5] = m.lAllowNull
        Dimension aNew[m.ii,5]
        For m.kk = 1 to Alen(m.aNew, 2)
            For m.jj = 1 to m.ii
                m.aNew[m.jj, m.kk] = m.aOld[m.jj, m.kk]
            EndFor
        EndFor
        m.cTemp = Sys(2015)
        Create Cursor (m.cTemp) from array aNew
        Append From Dbf(m.tcAls)
        Use Dbf(m.cTemp) Again In Select(m.tcAls) Alias (m.tcAls)
        Use in Select(m.cTemp)
    EndIf

    Select (m.nOldArea)
EndFunc