OpenSeqReader

Opens a sequential CSV reader for import records one at a time.

Syntax

expression.OpenSeqReader(configObj, [FilterColumns])

Parameters

Returns value

None

See also

GetRecord Method, CloseSeqReader Method, ParseConfig Property, CSVTextStream class.

Behavior

The OpenSeqReader method works in conjunction with the GetRecord method. The configObj parameter is an object with all the options considered by the parser during the import operation, see the ParseConfig Property documentation. The FilterColumns parameter is used to retrieve only certain fields from each CSV/TSV record. Filters can be strings representing the names of the fields determined with the header record, or numbers representing the position of the requested field. If no filters are defined, all fields of the requested records will be retrieved. Each call to the OpenSeqReader method will create a new conection to the CSV file.

📝Note

After opening a sequential reader, the user can read the CSV records one by one and implement logics to work with the extracted data. This makes it possible to mimic the more complex behavior of SQL statements.

☕Example

Private Sub OpenSeqReaderAndGetRecord()
    Dim CSVint As CSVinterface
    Dim csvRecord As CSVArrayList
            
    Set CSVint = New CSVinterface
    With CSVint
        .parseConfig.path = Environ("USERPROFILE") & "\Desktop\Demo_100000records.csv"
        Set .parseConfig.dialect = .SniffDelimiters(.parseConfig)
        .OpenSeqReader .parseConfig, 1, 2                                                  'Start sequential reader
                                                                                           'Import only 1st and 2nd fields
        Do
            Set csvRecord = .GetRecord                                                      'Get a record from CSV file
        Loop While Not csvRecord Is Nothing                                                 'Loop trhonght all records in file
    End With
    Set CSVint = Nothing
End Sub

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