如何在 VBA 脚本中编写 CTE 递归查询？

Question

我编写了一个 VBA 脚本，用于使用 OTA API 查询 HP ALM 数据库。

我想使用递归 CTE 查询数据库。我不知道如何在这个 VBA 脚本中编写该脚本。

VBA 脚本:::

Sub Extractor()

    Const QCADDRESS = "http://alm/qcbin"
    Const DOMAIN = "DOMAIN"
    Const PROJECT = "PROJECT"
    Const QCUSR = "user.name"
    Const QCPWD = "123456"

    Dim QCConnection, com, recset
    Dim XLS, Wkb, Wks, i

    Set QCConnection = CreateObject("TDApiOle80.TDConnection")
    QCConnection.InitConnectionEx QCADDRESS
    QCConnection.Login QCUSR, QCPWD
    QCConnection.Connect DOMAIN, PROJECT

    Set com = QCConnection.Command

    com.CommandText = "Select * from ALL_LISTS"

    Set recset = com.Execute

    Set XLS = CreateObject("Excel.Application")
    XLS.Visible = False
    Set Wkb = XLS.Workbooks.Add
    Set Wks = Wkb.Worksheets(1)

    i = 1
    Wks.Cells(i, 1).Value = "Data"


    If recset.RecordCount > 0 Then
    i = 2
    recset.First
    Do While Not (recset.EOR)
    Wks.Cells(i, 1).Value = recset.FieldValue(0) 'fieldvalue(0) because the query extract only 1 field.
    i = i + 1
    recset.Next
    Loop
    Wkb.SaveAs "C:\myfile.xls"
    End If


    Wkb.Close
    XLS.Quit

    QCConnection.Disconnect

    Set recset = Nothing
    Set com = Nothing
    Set QCConnection = Nothing
    Set XLS = Nothing
    Set Wkb = Nothing
    Set Wks = Nothing


End Sub

CTE 查询::::

with ReqCTE
as
(
SELECT
RQ_REQ_ID,
RQ_REQ_NAME,
RQ_FATHER_ID, 
0 as lvl
FROM
td.REQ
where
RQ_REQ_ID = {?Father_ID}

union all

select
Folders.RQ_REQ_ID,
Folders.RQ_REQ_NAME, 
Folders.RQ_FATHER_ID,
Child.lvl +1
from
ReqCTE as Child
join td.REQ as Folders on Folders.RQ_REQ_ID = Child.RQ_FATHER_ID
);

select * from ReqCTE;

Answer 1

这是您嵌入查询的代码，您的查询变量声明为 VBA 变量并在 SQL 脚本中引用：

Sub Extractor()

    Const QCADDRESS = "http://alm/qcbin"
    Const DOMAIN = "DOMAIN"
    Const PROJECT = "PROJECT"
    Const QCUSR = "user.name"
    Const QCPWD = "123456"
    Dim par(0) As Variant

    Dim QCConnection, com, recset
    Dim XLS, Wkb, Wks, i

    Set QCConnection = CreateObject("TDApiOle80.TDConnection")
    QCConnection.InitConnectionEx QCADDRESS
    QCConnection.Login QCUSR, QCPWD
    QCConnection.Connect DOMAIN, PROJECT

    Set com = QCConnection.Command
    par(0) = 4 'set parameter value for Father_ID in SQL

    com.CommandText = "with ReqCTE as (" & _
                        "SELECT RQ_REQ_ID, RQ_REQ_NAME, RQ_FATHER_ID, 0 as lvl FROM td.REQ " & _
                        "where RQ_REQ_ID = ? " & _
                        "Union all " & _
                        "select Folders.RQ_REQ_ID, Folders.RQ_REQ_NAME, Folders.RQ_FATHER_ID, Child.lvl +1 from ReqCTE as Child " & _
                        "join td.REQ as Folders on Folders.RQ_REQ_ID = Child.RQ_FATHER_ID); " & _
                        "select * from ReqCTE;"


    Set recset = com.Execute(, par)

    Set XLS = CreateObject("Excel.Application")
    XLS.Visible = False
    Set Wkb = XLS.Workbooks.Add
    Set Wks = Wkb.Worksheets(1)

    i = 1
    Wks.Cells(i, 1).Value = "Data"


    If recset.RecordCount > 0 Then
    i = 2
    recset.First
    Do While Not (recset.EOR)
    Wks.Cells(i, 1).Value = recset.FieldValue(0) 'fieldvalue(0) because the query extract only 1 field.
    i = i + 1
    recset.Next
    Loop
    Wkb.SaveAs "C:\myfile.xls"
    End If


    Wkb.Close
    XLS.Quit

    QCConnection.Disconnect

    Set recset = Nothing
    Set com = Nothing
    Set QCConnection = Nothing
    Set XLS = Nothing
    Set Wkb = Nothing
    Set Wks = Nothing


End Sub

已更新以避免注入