DataTable.Select 方法

參考

定義

命名空間:: System.Data

組件:: System.Data.Common.dll

組件:: System.Data.dll

組件:: netstandard.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

取得 DataRow 物件的陣列。

多載

Select()	取得所有 DataRow 物件的陣列。
Select(String)	取得所有符合篩選準則之 DataRow 物件的陣列。
Select(String, String)	取得按照指定排序順序符合篩選條件的所有 DataRow 物件之陣列。
Select(String, String, DataViewRowState)	取得符合篩選條件 (按照排序順序，並符合指定狀態) 的所有 DataRow 物件之陣列。

Select()

來源:: DataTable.cs

來源:: DataTable.cs

來源:: DataTable.cs

取得所有 DataRow 物件的陣列。

public:
 cli::array <System::Data::DataRow ^> ^ Select();

public System.Data.DataRow[] Select ();

member this.Select : unit -> System.Data.DataRow[]

Public Function Select () As DataRow()

傳回

DataRow[]

DataRow 物件的陣列。

範例

下列範例會透過 Select 方法傳回對象的陣列DataRow。

private void GetRows()
{
    // Get the DataTable of a DataSet.
    DataTable table = DataSet1.Tables["Suppliers"];
    DataRow[] rows = table.Select();

    // Print the value one column of each DataRow.
    for(int i = 0; i < rows.Length ; i++)
    {
        Console.WriteLine(rows[i]["CompanyName"]);
    }
}

Private Sub GetRows()
    ' Get the DataTable of a DataSet.
    Dim table As DataTable = DataSet1.Tables("Suppliers")
    Dim rows() As DataRow = table.Select()

    Dim i As Integer
    ' Print the value one column of each DataRow.
    For i = 0 to rows.GetUpperBound(0)
       Console.WriteLine(rows(i)("CompanyName"))
    Next i
End Sub

備註

若要確保適當的排序順序，請使用或 Select(String, String, DataViewRowState)指定排序準則Select(String, String)。

另請參閱

適用於

Select(String)

來源:: DataTable.cs

來源:: DataTable.cs

來源:: DataTable.cs

取得所有符合篩選準則之 DataRow 物件的陣列。

public:
 cli::array <System::Data::DataRow ^> ^ Select(System::String ^ filterExpression);

public System.Data.DataRow[] Select (string? filterExpression);

public System.Data.DataRow[] Select (string filterExpression);

member this.Select : string -> System.Data.DataRow[]

Public Function Select (filterExpression As String) As DataRow()

參數

filterExpression: String

用來篩選資料列的準則。

傳回

DataRow[]

DataRow 物件的陣列。

範例

下列範例會使用篩選表達式傳回物件的陣列 DataRow 。

private void GetRowsByFilter()
{
    DataTable table = DataSet1.Tables["Orders"];
    // Presuming the DataTable has a column named Date.
    string expression;
    expression = "Date > #1/1/00#";
    DataRow[] foundRows;

    // Use the Select method to find all rows matching the filter.
    foundRows = table.Select(expression);

    // Print column 0 of each returned row.
    for(int i = 0; i < foundRows.Length; i ++)
    {
        Console.WriteLine(foundRows[i][0]);
    }
}

Private Sub GetRowsByFilter()
    
    Dim table As DataTable = DataSet1.Tables("Orders")

    ' Presuming the DataTable has a column named Date.
    Dim expression As String
    expression = "Date > #1/1/00#"
    Dim foundRows() As DataRow

    ' Use the Select method to find all rows matching the filter.
    foundRows = table.Select(expression)

    Dim i As Integer
    ' Print column 0 of each returned row.
    For i = 0 to foundRows.GetUpperBound(0)
       Console.WriteLine(foundRows(i)(0))
    Next i
End Sub

備註

若要建立 filterExpression 自變數，請使用套用至 DataColumn 類別屬性值的 Expression 相同規則來建立篩選。

若要確保適當的排序順序，請使用或 Select(String, String, DataViewRowState)指定排序準則Select(String, String)。

如果篩選上的數據行包含 Null 值，則不會是結果的一部分。

另請參閱

適用於

Select(String, String)

來源:: DataTable.cs

來源:: DataTable.cs

來源:: DataTable.cs

取得按照指定排序順序符合篩選條件的所有 DataRow 物件之陣列。

public:
 cli::array <System::Data::DataRow ^> ^ Select(System::String ^ filterExpression, System::String ^ sort);

public System.Data.DataRow[] Select (string? filterExpression, string? sort);

public System.Data.DataRow[] Select (string filterExpression, string sort);

member this.Select : string * string -> System.Data.DataRow[]

Public Function Select (filterExpression As String, sort As String) As DataRow()

參數

filterExpression: String

用來篩選資料列的準則。

sort: String

指定資料行和排序方向的字串。

傳回

DataRow[]

符合篩選條件運算式的 DataRow 物件之陣列。

範例

下列範例會使用篩選表達式傳回物件的陣列 DataRow 。

using System;
using System.Data;

public class A {

   public static void Main() {
      DataTable table = new DataTable("Orders");
      table.Columns.Add("OrderID", typeof(Int32));
      table.Columns.Add("OrderQuantity", typeof(Int32));
      table.Columns.Add("CompanyName", typeof(string));
      table.Columns.Add("Date", typeof(DateTime));

      DataRow newRow = table.NewRow();
      newRow["OrderID"] = 1;
      newRow["OrderQuantity"] = 3;
      newRow["CompanyName"] = "NewCompanyName";
      newRow["Date"] = "1979, 1, 31";

      // Add the row to the rows collection.
      table.Rows.Add(newRow);

      DataRow newRow2 = table.NewRow();
      newRow2["OrderID"] = 2;
      newRow2["OrderQuantity"] = 2;
      newRow2["CompanyName"] = "NewCompanyName1";
      table.Rows.Add(newRow2);

      DataRow newRow3 = table.NewRow();
      newRow3["OrderID"] = 3;
      newRow3["OrderQuantity"] = 2;
      newRow3["CompanyName"] = "NewCompanyName2";
      table.Rows.Add(newRow3);

      // Presuming the DataTable has a column named Date.
      string expression = "Date = '1/31/1979' or OrderID = 2";
      // string expression = "OrderQuantity = 2 and OrderID = 2";

      // Sort descending by column named CompanyName.
      string sortOrder = "CompanyName ASC";
      DataRow[] foundRows;

      // Use the Select method to find all rows matching the filter.
      foundRows = table.Select(expression, sortOrder);

      // Print column 0 of each returned row.
      for (int i = 0; i < foundRows.Length; i++)
         Console.WriteLine(foundRows[i][2]);
   }
}

Imports System.Data

Public Class A

   Public Shared Sub Main()
      Dim table As New DataTable("Orders")
      table.Columns.Add("OrderID", GetType(Int32))
      table.Columns.Add("OrderQuantity", GetType(Int32))
      table.Columns.Add("CompanyName", GetType(String))
      table.Columns.Add("Date", GetType(DateTime))

      Dim newRow As DataRow = table.NewRow()
      newRow("OrderID") = 1
      newRow("OrderQuantity") = 3
      newRow("CompanyName") = "NewCompanyName"
      newRow("Date") = "1979, 1, 31"

      ' Add the row to the rows collection.
      table.Rows.Add(newRow)

      Dim newRow2 As DataRow = table.NewRow()
      newRow2("OrderID") = 2
      newRow2("OrderQuantity") = 2
      newRow2("CompanyName") = "NewCompanyName1"
      table.Rows.Add(newRow2)

      Dim newRow3 As DataRow = table.NewRow()
      newRow3("OrderID") = 3
      newRow3("OrderQuantity") = 2
      newRow3("CompanyName") = "NewCompanyName2"
      table.Rows.Add(newRow3)

      ' Presuming the DataTable has a column named Date.
      Dim expression As String = "Date = '1/31/1979' or OrderID = 2"
      ' Dim expression As String = "OrderQuantity = 2 and OrderID = 2"

      ' Sort descending by column named CompanyName.
      Dim sortOrder As String = "CompanyName ASC"
      Dim foundRows As DataRow()

      ' Use the Select method to find all rows matching the filter.
      foundRows = table.[Select](expression, sortOrder)

      ' Print column 0 of each returned row.
      For i As Integer = 0 To foundRows.Length - 1
         Console.WriteLine(foundRows(i)(2))
      Next
   End Sub
End Class

備註

若要形成自 filterExpression 變數，請使用相同的規則來建立 DataColumn 類別的 Expression 屬性值。自 Sort 變數也會使用相同的規則來建立類別的 Expression 字串。

如果篩選上的數據行包含 Null 值，則不會是結果的一部分。

另請參閱

適用於

Select(String, String, DataViewRowState)

來源:: DataTable.cs

來源:: DataTable.cs

來源:: DataTable.cs

取得符合篩選條件 (按照排序順序，並符合指定狀態) 的所有 DataRow 物件之陣列。

public:
 cli::array <System::Data::DataRow ^> ^ Select(System::String ^ filterExpression, System::String ^ sort, System::Data::DataViewRowState recordStates);

public System.Data.DataRow[] Select (string? filterExpression, string? sort, System.Data.DataViewRowState recordStates);

public System.Data.DataRow[] Select (string filterExpression, string sort, System.Data.DataViewRowState recordStates);

member this.Select : string * string * System.Data.DataViewRowState -> System.Data.DataRow[]

Public Function Select (filterExpression As String, sort As String, recordStates As DataViewRowState) As DataRow()

參數

filterExpression: String

用來篩選資料列的準則。

sort: String

指定資料行和排序方向的字串。

recordStates: DataViewRowState

其中一個 DataViewRowState 值。

傳回

DataRow[]

DataRow 物件的陣列。

範例

下列範例會使用篩選表達式和記錄狀態來傳回物件的陣列 DataRow 。

private static void GetRowsByFilter()
{
    DataTable customerTable = new DataTable("Customers");
    // Add columns
    customerTable.Columns.Add("id", typeof(int));
    customerTable.Columns.Add("name", typeof(string));

    // Set PrimaryKey
    customerTable.Columns[ "id" ].Unique = true;
    customerTable.PrimaryKey = new DataColumn[]
        { customerTable.Columns["id"] };

    // Add ten rows
    for(int id=1; id<=10; id++)
    {
        customerTable.Rows.Add(
            new object[] { id, string.Format("customer{0}", id) });
    }
    customerTable.AcceptChanges();

    // Add another ten rows
    for(int id=11; id<=20; id++)
    {
        customerTable.Rows.Add(
            new object[] { id, string.Format("customer{0}", id) });
    }

    string expression;
    string sortOrder;

    expression = "id > 5";
    // Sort descending by column named CompanyName.
    sortOrder = "name DESC";
    // Use the Select method to find all rows matching the filter.
    DataRow[] foundRows =
        customerTable.Select(expression, sortOrder,
        DataViewRowState.Added);

    PrintRows(foundRows, "filtered rows");

    foundRows = customerTable.Select();
    PrintRows(foundRows, "all rows");
}

private static void PrintRows(DataRow[] rows, string label)
{
    Console.WriteLine("\n{0}", label);
    if(rows.Length <= 0)
    {
        Console.WriteLine("no rows found");
        return;
    }
    foreach(DataRow row in rows)
    {
        foreach(DataColumn column in row.Table.Columns)
        {
            Console.Write("\table {0}", row[column]);
        }
        Console.WriteLine();
    }
}

Private Sub GetRowsByFilter()

    Dim customerTable As New DataTable("Customers")

    ' Add columns
    customerTable.Columns.Add("id", GetType(Integer))
    customerTable.Columns.Add("name", GetType(String))

    ' Set PrimaryKey
    customerTable.Columns("id").Unique = True
    customerTable.PrimaryKey = New DataColumn() _
        {customerTable.Columns("id")}

    ' add ten rows
    Dim id As Integer
    For id = 1 To 10
        customerTable.Rows.Add( _
        New Object() {id, String.Format("customer{0}", id)})
    Next id
    customerTable.AcceptChanges()

    ' add another ten rows
    For id = 11 To 20
        customerTable.Rows.Add( _
        New Object() {id, String.Format("customer{0}", id)})
    Next id

    Dim expression As String
    Dim sortOrder As String

    expression = "id > 5"
    ' Sort descending by CompanyName column.
    sortOrder = "name DESC"

    ' Use the Select method to find all rows matching the filter.
    Dim foundRows As DataRow() = _
        customerTable.Select(expression, sortOrder, _
        DataViewRowState.Added)

    PrintRows(foundRows, "filtered rows")

    foundRows = customerTable.Select()
    PrintRows(foundRows, "all rows")
End Sub

Private Sub PrintRows(ByVal rows() As DataRow, ByVal label As String)
    Console.WriteLine("\n{0}", label)
    If rows.Length <= 0 Then
        Console.WriteLine("no rows found")
        Exit Sub
    End If

    Dim row As DataRow
    Dim column As DataColumn
    For Each row In rows
        For Each column In row.Table.Columns
            Console.Write("\table {0}", row(column))
        Next column
        Console.WriteLine()
    Next row
End Sub

備註

如果篩選上的數據行包含 Null 值，則不會是結果的一部分。

另請參閱

適用於

共用方式為

DataTable.Select 方法

定義

多載

Select()

傳回

範例

備註

另請參閱

適用於

Select(String)

參數

傳回

範例

備註

另請參閱

適用於

Select(String, String)

參數

傳回

範例

備註

另請參閱

適用於

Select(String, String, DataViewRowState)

參數

傳回

範例

備註

另請參閱

適用於

其他資源