Question

我一直在使用Allen Browne的ConcatRelated()函数，但我意识到数据集较大，数据不完整。

这个函数是否有字符限制，如果有，是否有不同的函数/ UDF可以达到相同的结果？

这是函数： - 并链接回原始线程http://allenbrowne.com/func-concat.html

Public Function ConcatRelated(strField As String, _
    strTable As String, _
    Optional strWhere As String, _
    Optional strOrderBy As String, _
    Optional strSeparator = ", ") As Variant
On Error GoTo Err_Handler
    'Purpose:   Generate a concatenated string of related records.
    'Return:    String variant, or Null if no matches.
    'Arguments: strField = name of field to get results from and concatenate.
    '           strTable = name of a table or query.
    '           strWhere = WHERE clause to choose the right values.
    '           strOrderBy = ORDER BY clause, for sorting the values.
    '           strSeparator = characters to use between the concatenated values.
    'Notes:     1. Use square brackets around field/table names with spaces or odd characters.
    '           2. strField can be a Multi-valued field (A2007 and later), but strOrderBy cannot.
    '           3. Nulls are omitted, zero-length strings (ZLSs) are returned as ZLSs.
    '           4. Returning more than 255 characters to a recordset triggers this Access bug:
    '               http://allenbrowne.com/bug-16.html
    Dim rs As DAO.Recordset         'Related records
    Dim rsMV As DAO.Recordset       'Multi-valued field recordset
    Dim strSql As String            'SQL statement
    Dim strOut As String            'Output string to concatenate to.
    Dim lngLen As Long              'Length of string.
    Dim bIsMultiValue As Boolean    'Flag if strField is a multi-valued field.

    'Initialize to Null
    ConcatRelated = Null

    'Build SQL string, and get the records.
    strSql = "SELECT " & strField & " FROM " & strTable
    If strWhere <> vbNullString Then
        strSql = strSql & " WHERE " & strWhere
    End If
    If strOrderBy <> vbNullString Then
        strSql = strSql & " ORDER BY " & strOrderBy
    End If
    Set rs = DBEngine(0)(0).OpenRecordset(strSql, dbOpenDynaset)
    'Determine if the requested field is multi-valued (Type is above 100.)
    bIsMultiValue = (rs(0).Type > 100)

    'Loop through the matching records
    Do While Not rs.EOF
        If bIsMultiValue Then
            'For multi-valued field, loop through the values
            Set rsMV = rs(0).Value
            Do While Not rsMV.EOF
                If Not IsNull(rsMV(0)) Then
                    strOut = strOut & rsMV(0) & strSeparator
                End If
                rsMV.MoveNext
            Loop
            Set rsMV = Nothing
        ElseIf Not IsNull(rs(0)) Then
            strOut = strOut & rs(0) & strSeparator
        End If
        rs.MoveNext
    Loop
    rs.Close

    'Return the string without the trailing separator.
    lngLen = Len(strOut) - Len(strSeparator)
    If lngLen > 0 Then
        ConcatRelated = Left(strOut, lngLen)
    End If

Exit_Handler:
    'Clean up
    Set rsMV = Nothing
    Set rs = Nothing
    Exit Function

Err_Handler:
    MsgBox "Error " & Err.Number & ": " & Err.Description, vbExclamation, "ConcatRelated()"
    Resume Exit_Handler
End Function

修改
我正在使用VBA并运行Into语句。如果我先生成表然后插入数据会更好吗？

当前结构

DoCmd.RunSQL "Select DISTINCT [ImportTable].DSFNum, 

ConcatRelated('[Item]','[ImportTable]','[DSFNum] =' & [DSFNum]) AS Item, 
ConcatRelated('[Count]','[ImportTable]','[DSFNum] =' & [DSFNum]) AS Count 
INTO [OneRowTable] 
FROM [ImportTable]"

Answer 1

所有相关信息都可以在ConcatRelated函数的代码中找到：

注意：将超过255个字符返回到记录集会触发此Access错误：   http://allenbrowne.com/bug-16.html

正如在该页面上可以找到的那样，问题不在于功能，而是Access中的文本字段不能包含那么多字符的事实，并且可以通过使用

之类的东西来修复

SELECT ID, MuchText FROM StructureOnly 
UNION ALL
SELECT ID, ConcatRelated(something, table, where) AS MuchText FROM LotsaText;

MuchText是备忘录字段

使用VBA和记录集的解决方法：

Dim rsSelect As DAO.Recordset
Dim rsInsert As DAO.Recordset
Dim db As DAO.Database
Set db = CurrentDb
Set rsSelect = db.OpenRecordset ("Select DISTINCT [ImportTable].DSFNum FROM [ImportTable]")
Set rsInsert = db.OpenRecordset("OneRowTable")
Do While Not rsSelect.EOF
    rsInsert.AddNew
    rsInsert!DSFNum = rsSelect!DSFNum
    rsInsert!Item = ConcatRelated("[Item]","[ImportTable]","[DSFNum] =" & rsSelect!DSFNum)
    rsInsert!Count = ConcatRelated("[Count]","[ImportTable]","[DSFNum] =" & rsSelect!DSFNum)
    rsInsert.Update
    rsSelect.MoveNext
Loop

ConcatRelated（）函数的字符限制

1 个答案: