access合并多行列数据到一行，类似于mysql的group_concact()函数

roger2001c

Concatenate fields in same table	Author(s)
Dev Ashish
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(Q)    I need to concatenate a field in the format "Value1; Value2; Value3" etc. for each unique value of another field in the same table.  How can I do this? 　　(A)    Using the fConcatFld function,  in the Northwind database, the following query should return a concatenated list of all CustomerIDs if you group by ContactTitle. 　　使用方式： SELECT ContactTitle, fConcatFld("Customers","ContactTitle","CustomerID","string",[ContactTitle]) AS Customers FROM Customers GROUP BY ContactTitle; 　　 　　参数说明： fConcatFld参数说明 stTable As String 表名称  _stForFld As String,  查询的条件字段名称 _stFldToConcat As String,  合并的字段名称 _ stForFldType As String, 合并字段的类型 _vForFldVal As Variant 合并字段的查询条件 '************ Code Start ********** 'This code was originally written by Dev Ashish 'It is not to be altered or distributed, 'except as part of an application. 'You are free to use it in any application, 'provided the copyright notice is left unchanged. ' 'Code Courtesy of 'Dev Ashish ' Function fConcatFld(stTable As String, _ stForFld As String, _ stFldToConcat As String, _ stForFldType As String, _ vForFldVal As Variant) _ As String 'Returns mutiple field values for each unique value 'of another field in a single table 'in a semi-colon separated format. ' 'Usage Examples: '   ?fConcatFld(("Customers","ContactTitle","CustomerID", _ '                "string","Owner") 'Where  Customers     = The parent Table '       ContactTitle  = The field whose values to use for lookups '       CustomerID    = Field name to concatenate '       string        = DataType of ContactTitle field '       Owner         = Value on which to return concatenated CustomerID ' Dim lodb As Database, lors As Recordset Dim lovConcat As Variant, loCriteria As String Dim loSQL As String Const cQ = """" On Error GoTo Err_fConcatFld lovConcat = Null Set lodb = CurrentDb loSQL = "SELECT [" & stFldToConcat & "] FROM [" loSQL = loSQL & stTable & "] WHERE " Select Case stForFldType Case "String": loSQL = loSQL & "[" & stForFld & "] =" & cQ & vForFldVal & cQ Case "Long", "Integer", "Double":    'AutoNumber is Type Long loSQL = loSQL & "[" & stForFld & "] = " & vForFldVal Case Else GoTo Err_fConcatFld End Select Set lors = lodb.OpenRecordset(loSQL, dbOpenSnapshot) 'Are we sure that duplicates exist in stFldToConcat With lors If .RecordCount <> 0 Then 'start concatenating records Do While Not .EOF lovConcat = lovConcat & lors(stFldToConcat) & "; " .MoveNext Loop Else GoTo Exit_fConcatFld End If End With 'That's it... you should have a concatenated string now 'Just Trim the trailing ; fConcatFld = Left(lovConcat, Len(lovConcat) - 2) Exit_fConcatFld: Set lors = Nothing: Set lodb = Nothing Exit Function Err_fConcatFld: MsgBox "Error#: " & Err.Number & vbCrLf & Err.Description Resume Exit_fConcatFld End Function '************ Code End **********