Cara: Menggabungkan Konten dari File yang Berbeda (LINQ) (Visual Basic)

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Contoh ini menunjukkan cara menggabungkan data dari dua file yang dipisahkan koma yang berbagi nilai umum yang digunakan sebagai kunci yang cocok. Teknik ini berguna jika Anda harus menggabungkan data dari dua spreadsheet, atau dari spreadsheet dan dari file yang memiliki format lain, ke dalam file baru. Anda dapat memodifikasi contoh untuk bekerja dengan semua jenis teks terstruktur.

Untuk membuat file data

  1. Salin baris berikut ke dalam file bernama scores.csv dan simpan ke folder proyek Anda. File merepresentasikan data spreadsheet. Kolom 1 adalah ID siswa, dan kolom 2 hingga 5 adalah skor tes.

    111, 97, 92, 81, 60
112, 75, 84, 91, 39
113, 88, 94, 65, 91
114, 97, 89, 85, 82
115, 35, 72, 91, 70
116, 99, 86, 90, 94
117, 93, 92, 80, 87
118, 92, 90, 83, 78
119, 68, 79, 88, 92
120, 99, 82, 81, 79
121, 96, 85, 91, 60
122, 94, 92, 91, 91

  2. Salin baris berikut ke dalam file bernama names.csv dan simpan ke folder proyek Anda. File merepresentasikan spreadsheet yang berisi nama belakang siswa, nama depan, dan ID siswa.

    Omelchenko,Svetlana,111
O'Donnell,Claire,112
Mortensen,Sven,113
Garcia,Cesar,114
Garcia,Debra,115
Fakhouri,Fadi,116
Feng,Hanying,117
Garcia,Hugo,118
Tucker,Lance,119
Adams,Terry,120
Zabokritski,Eugene,121
Tucker,Michael,122

Contoh

Imports System.Collections.Generic
Imports System.Linq

Class JoinStrings

    Shared Sub Main()

        ' Join content from spreadsheet files that contain
        ' related information. names.csv contains the student name
        ' plus an ID number. scores.csv contains the ID and a
        ' set of four test scores. The following query joins
        ' the scores to the student names by using ID as a
        ' matching key.

        Dim names As String() = System.IO.File.ReadAllLines("../../../names.csv")
        Dim scores As String() = System.IO.File.ReadAllLines("../../../scores.csv")

        ' Name:    Last[0],       First[1],  ID[2],     Grade Level[3]
        '          Omelchenko,    Svetlana,  111,       2
        ' Score:   StudentID[0],  Exam1[1]   Exam2[2],  Exam3[3],  Exam4[4]
        '          111,           97,        92,        81,        60

        ' This query joins two dissimilar spreadsheets based on common ID value.
        ' Multiple from clauses are used instead of a join clause
        ' in order to store results of id.Split.
        Dim scoreQuery1 = From name In names
                         Let n = name.Split(New Char() {","})
                            From id In scores
                            Let n2 = id.Split(New Char() {","})
                            Where Convert.ToInt32(n(2)) = Convert.ToInt32(n2(0))
                            Select n(0) & "," & n2(1) & "," & n2(2) & "," & n2(3) & "," &  n2(4)

        ' Pass a query variable to a Sub and execute it there.
        ' The query itself is unchanged.
        OutputQueryResults(scoreQuery1, "Merge two spreadsheets:")

        ' Keep console window open in debug mode.
        Console.WriteLine("Press any key to exit.")
        Console.ReadKey()
    End Sub

    Shared Sub OutputQueryResults(ByVal query As IEnumerable(Of String), ByVal message As String)

        Console.WriteLine(System.Environment.NewLine & message)
        For Each item As String In query
            Console.WriteLine(item)
        Next
        Console.WriteLine(query.Count & " total names in list")

    End Sub
End Class
' Output:
' Merge two spreadsheets:
' Omelchenko, 97, 92, 81, 60
' O'Donnell, 75, 84, 91, 39
' Mortensen, 88, 94, 65, 91
' Garcia, 97, 89, 85, 82
' Garcia, 35, 72, 91, 70
' Fakhouri, 99, 86, 90, 94
' Feng, 93, 92, 80, 87
' Garcia, 92, 90, 83, 78
' Tucker, 68, 79, 88, 92
' Adams, 99, 82, 81, 79
' Zabokritski, 96, 85, 91, 60
' Tucker, 94, 92, 91, 91
' 12 total names in list

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