解析Access中的字符串值

Question

我正在将sql导入到我的Access数据库中，并且正在将数据解析到正确的表和字段中。我再次转向你们的大师们以帮助解决问题

其中一个导入的字段包含逗号分隔的值，需要进行分隔。字符串中可能存在1到10个可能的值。

PHO,Rosgen,NRCS,EMAP,T-DL,YSI-DL 

我已经想通了，如果我做的所有值相同的长度（比如4个字符），我可以得到第一，最后和第一逗号之后解析，但似乎无法得到提取的中间值正确。

SELECT Left([FieldForms],InStr([FieldForms],",")-1) AS DEQ_SampleTypeID 
FROM tblSiteVisit 
UNION ALL 
SELECT Mid([FieldForms],InStr([FieldForms],",")+1,4) AS DEQ_SampleTypeID 
FROM tblSiteVisit 
UNION ALL 
SELECT Mid([FieldForms], 11, 4) AS DEQ_SampleTypeID 
FROM tblSiteVisit 
UNION ALL 
SELECT Mid([FieldForms], 16, 4) AS DEQ_SampleTypeID 
FROM tblSiteVisit 
UNION ALL 
SELECT Mid([FieldForms], 21, 4) AS DEQ_SampleTypeID 
FROM tblSiteVisit 
UNION ALL 
SELECT Mid([FieldForms],InStrRev([FieldForms],",")-4,4) AS DEQ_SampleTypeID 
FROM tblSiteVisit 
UNION ALL 
SELECT Right([FieldForms],InStr([FieldForms],",")-1) AS DEQ_SampleTypeID 
FROM tblSiteVisit 

如果我使用InStrRev或右边的功能，我得到重复，如果有比也使用空行的中期功能结果的最大较少。

有没有办法来解析出像这样的字符串，只能从字符串

Answer 1

将下面的功能集成到一个模块得到结果：

Function CountCSWords (ByVal S) As Integer 
    ' Counts the words in a string that are separated by commas. 

    Dim WC As Integer, Pos As Integer 
    If VarType(S) <> 8 Or Len(S) = 0 Then 
     CountCSWords = 0 
     Exit Function 
    End If 
    WC = 1 
    Pos = InStr(S, ",") 
    Do While Pos > 0 
     WC = WC + 1 
     Pos = InStr(Pos + 1, S, ",") 
    Loop 
    CountCSWords = WC 
    End Function 

    Function GetCSWord (ByVal S, Indx As Integer) 
    ' Returns the nth word in a specific field. 

    Dim WC As Integer, Count As Integer, SPos As Integer, EPos As Integer 
    WC = CountCSWords(S) 
    If Indx < 1 Or Indx > WC Then 
     GetCSWord = Null 
     Exit Function 
    End If 
    Count = 1 
    SPos = 1 
    For Count = 2 To Indx 
     SPos = InStr(SPos, S, ",") + 1 
    Next Count 
    EPos = InStr(SPos, S, ",") - 1 
    If EPos <= 0 Then EPos = Len(S) 
    GetCSWord = Trim(Mid(S, SPos, EPos - SPos + 1)) 
    End Function 

然后，把一个场在您的查询像这样的：

MyFirstField: GetCSWord([FieldForms],1) 

把另一个像这样：

MySecondField: GetCSWord([FieldForms],2) 

等......尽可能多的你需要。

Answer 2

这VBA代码在tblSiteVisit从FieldForms读取文本值，分割该文本为子，然后存储每个在在一个新行DEQ_SampleTypeID加入tblDestination的子串。

Dim astrItems() As String 
Dim db As DAO.database 
Dim i As Long 
Dim qdf As DAO.QueryDef 
Dim rs As DAO.Recordset 
Dim strInsert As String 

strInsert = "INSERT INTO tblDestination (DEQ_SampleTypeID)" & vbCrLf & _ 
    "VALUES ([array_item]);" 

Set db = CurrentDb 
Set rs = db.OpenRecordset("tblSiteVisit", dbOpenTable, dbOpenSnapshot) 
Set qdf = db.CreateQueryDef(vbNullString, strInsert) 
Do While Not rs.EOF 
    astrItems = Split(rs!FieldForms, ",") 
    For i = 0 To UBound(astrItems) 
     qdf.Parameters("array_item") = astrItems(i) 
     qdf.Execute dbFailOnError 
    Next 
    rs.MoveNext 
Loop 
rs.Close 
Set rs = Nothing 
Set qdf = Nothing 
Set db = Nothing