Creazione, modifica e rimozione di indici

Articolo
03/20/2013

Nella gerarchia SMO (SQL Server Management Objects) gli indici sono rappresentati dall'oggetto Index. Le colonne indicizzate sono rappresentate da una raccolta di oggetti IndexedColumn rappresentati dalla proprietà IndexedColumns.

È possibile creare un indice in una colonna XML specificando la proprietà IsXmlIndex dell'oggetto Index.

Esempi

Per utilizzare qualsiasi esempio di codice fornito, è necessario scegliere l'ambiente di programmazione, il modello di programmazione e il linguaggio di programmazione per la creazione dell'applicazione. Per ulteriori informazioni, vedere Creare un progetto SMO per Visual Basic in Visual Studio .NET o Creare un progetto SMO per Visual C# in Visual Studio .NET.

Creazione di un indice composto non cluster in Visual Basic

In questo esempio di codice viene illustrato come creare un indice composto non cluster. Per un indice composto, aggiungere più di una colonna all'indice. Per un indice non cluster, impostare la proprietà IsClustered su False.

' /r:Microsoft.SqlServer.Smo.dll
' /r:Microsoft.SqlServer.ConnectionInfo.dll
' /r:Microsoft.SqlServer.SqlEnum.dll
' /r:Microsoft.SqlServer.Management.Sdk.Sfc.dll

Imports Microsoft.SqlServer.Management.Smo
Public Class A
    Public Shared Sub Main()
        ' Connect to the local, default instance of SQL Server. 
        Dim srv As Server
        srv = New Server()

        ' Reference the AdventureWorks2012 database. 
        Dim db As Database
        db = srv.Databases("AdventureWorks2012")

        ' Declare a Table object and reference the HumanResources table. 
        Dim tb As Table
        tb = db.Tables("Employee", "HumanResources")

        ' Define an Index object variable by providing the parent table and index name in the constructor. 
        Dim idx As Index
        idx = New Index(tb, "TestIndex")

        ' Add indexed columns to the index. 
        Dim icol1 As IndexedColumn
        icol1 = New IndexedColumn(idx, "BusinessEntityID", True)
        idx.IndexedColumns.Add(icol1)
        Dim icol2 As IndexedColumn
        icol2 = New IndexedColumn(idx, "HireDate", True)
        idx.IndexedColumns.Add(icol2)

        ' Set the index properties. 
        idx.IndexKeyType = IndexKeyType.DriUniqueKey
        idx.IsClustered = False
        idx.FillFactor = 50

        ' Create the index on the instance of SQL Server. 
        idx.Create()

        ' Modify the page locks property. 
        idx.DisallowPageLocks = True

        ' Run the Alter method to make the change on the instance of SQL Server. 
        idx.Alter()

        ' Remove the index from the table. 
        idx.Drop()
    End Sub
End Class

Creazione di un indice composto non cluster in Visual C#

// /r:Microsoft.SqlServer.Smo.dll
// /r:Microsoft.SqlServer.ConnectionInfo.dll
// /r:Microsoft.SqlServer.SqlEnum.dll
// /r:Microsoft.SqlServer.Management.Sdk.Sfc.dll

using Microsoft.SqlServer.Management.Smo;

public class A {
   public static void Main() {
      // Connect to the local, default instance of SQL Server. 
      Server srv;
      srv = new Server();

      // Reference the AdventureWorks2012 database. 
      Database db;
      db = srv.Databases["AdventureWorks2012"];

      // Declare a Table object and reference the HumanResources table. 
      Table tb;
      tb = db.Tables["Employee", "HumanResources"];

      // Define an Index object variable by providing the parent table and index name in the constructor. 
      Index idx;
      idx = new Index(tb, "TestIndex");

      // Add indexed columns to the index. 
      IndexedColumn icol1;
      icol1 = new IndexedColumn(idx, "BusinessEntityID", true);
      idx.IndexedColumns.Add(icol1);
      IndexedColumn icol2;
      icol2 = new IndexedColumn(idx, "HireDate", true);
      idx.IndexedColumns.Add(icol2);

      // Set the index properties. 
      idx.IndexKeyType = IndexKeyType.DriUniqueKey;
      idx.IsClustered = false;
      idx.FillFactor = 50;

      // Create the index on the instance of SQL Server. 
      idx.Create();

      // Modify the page locks property. 
      idx.DisallowPageLocks = true;

      // Run the Alter method to make the change on the instance of SQL Server. 
      idx.Alter();

      // Remove the index from the table. 
      idx.Drop();
   }
}

Creazione di un indice composto non cluster in PowerShell

# Set the path context to the local, default instance of SQL Server and to the
#database tables in Adventureworks2012
CD \sql\localhost\default\databases\AdventureWorks2012\Tables\

#Get a reference to the table
$tb = get-item HumanResources.Employee

#Define an Index object variable by providing the parent table and index name in the constructor. 
$idx = New-Object -TypeName Microsoft.SqlServer.Management.SMO.Index -argumentlist $tb, "TestIndex"

#Add indexed columns to the index. 
$icol1 = New-Object -TypeName Microsoft.SqlServer.Management.SMO.IndexedColumn `
-argumentlist $idx, "BusinessEntityId", $true
$idx.IndexedColumns.Add($icol1)

$icol2 = New-Object -TypeName Microsoft.SqlServer.Management.SMO.IndexedColumn `
-argumentlist $idx, "HireDate", $true
$idx.IndexedColumns.Add($icol2)

#Set the index properties. 
$idx.IndexKeyType = [Microsoft.SqlServer.Management.SMO.IndexKeyType]::DriUniqueKey 
$idx.IsClustered = $false
$idx.FillFactor = 50

#Create the index on the instance of SQL Server. 
$idx.Create()

#Modify the page locks property. 
$idx.DisallowPageLocks = $true

#Run the Alter method to make the change on the instance of SQL Server. 
$idx.Alter()

#Remove the index from the table. 
$idx.Drop();

Creazione di un indice XML in Visual Basic

In questo esempio di codice viene illustrato come creare un indice XML in un tipo di dati XML. Il tipo di dati XML è una raccolta di XML Schema denominata MySampleCollection, creata in Utilizzo di XML Schema. Gli indici XML presentano alcune restrizioni, una delle quali è rappresentata dal fatto che devono essere creati in una tabella che dispone già di una chiave primaria cluster.

' /r:Microsoft.SqlServer.Smo.dll
' /r:Microsoft.SqlServer.ConnectionInfo.dll
' /r:Microsoft.SqlServer.SqlEnum.dll
' /r:Microsoft.SqlServer.Management.Sdk.Sfc.dll

Imports Microsoft.SqlServer.Management.Smo

Public Class A
    Public Shared Sub Main()
        ' Connect to the local, default instance of SQL Server. 
        Dim srv As Server
        srv = New Server()
        Dim db1 As Database = srv.Databases("TESTDB")
        ' Define a Table object variable and add an XML type column. 
        Dim tb As New Table(db1, "XmlTable3")

        Dim mySample As New XmlSchemaCollection(db1, "Sample4", "dbo")
        mySample.Text = "<xsd:schema xmlns:xsd=""http://www.w3.org/2001/XMLSchema"" targetNamespace=""NS2""> <xsd:element name=""elem1"" type=""xsd:integer""/></xsd:schema>"
        mySample.Create()

        Dim col11 As Column

        ' This sample requires that an XML schema type called MySampleCollection exists on the database. 
        col11 = New Column(tb, "XMLValue", DataType.Xml("Sample4"))

        ' Add another integer column that can be made into a unique, primary key. 
        tb.Columns.Add(col11)
        Dim col21 As Column
        col21 = New Column(tb, "Number", DataType.Int)
        col21.Nullable = False
        tb.Columns.Add(col21)

        ' Create the table of the instance of SQL Server. 
        tb.Create()

        ' Create a unique, clustered, primary key index on the integer column. This is required for an XML index. 
        Dim cp As Index
        cp = New Index(tb, "clusprimindex3")
        cp.IsClustered = True
        cp.IndexKeyType = IndexKeyType.DriPrimaryKey
        Dim cpcol As IndexedColumn
        cpcol = New IndexedColumn(cp, "Number", True)
        cp.IndexedColumns.Add(cpcol)
        cp.Create()

        ' Define and XML Index object variable by supplying the parent table and the XML index name arguments in the constructor. 
        Dim i As Index
        i = New Index(tb, "xmlindex")
        Dim ic As IndexedColumn
        ic = New IndexedColumn(i, "XMLValue", True)
        i.IndexedColumns.Add(ic)

        ' Create the XML index on the instance of SQL Server. 
        i.Create()
    End Sub
End Class

Creazione di un indice XML in Visual C#

// /r:Microsoft.SqlServer.Smo.dll
// /r:Microsoft.SqlServer.ConnectionInfo.dll
// /r:Microsoft.SqlServer.SqlEnum.dll
// /r:Microsoft.SqlServer.Management.Sdk.Sfc.dll

using Microsoft.SqlServer.Management.Smo;

public class A {
   public static void Main() {
      // Connect to the local, default instance of SQL Server. 
      Server srv;
      srv = new Server();
      Database db1 = srv.Databases["TESTDB"];
      // Define a Table object variable and add an XML type column. 
      Table tb = new Table(db1, "XmlTable3");

      XmlSchemaCollection mySample = new XmlSchemaCollection(db1, "Sample4", "dbo");
      mySample.Text = "<xsd:schema xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" targetNamespace=\"NS2\"> <xsd:element name=\"elem1\" type=\"xsd:integer\"/></xsd:schema>";
      mySample.Create();

      Column col11;

      // This sample requires that an XML schema type called MySampleCollection exists on the database. 
      col11 = new Column(tb, "XMLValue", DataType.Xml("Sample4"));

      // Add another integer column that can be made into a unique, primary key. 
      tb.Columns.Add(col11);
      Column col21;
      col21 = new Column(tb, "Number", DataType.Int);
      col21.Nullable = false;
      tb.Columns.Add(col21);

      // Create the table of the instance of SQL Server. 
      tb.Create();

      // Create a unique, clustered, primary key index on the integer column. This is required for an XML index. 
      Index cp;
      cp = new Index(tb, "clusprimindex3");
      cp.IsClustered = true;
      cp.IndexKeyType = IndexKeyType.DriPrimaryKey;
      IndexedColumn cpcol;
      cpcol = new IndexedColumn(cp, "Number", true);
      cp.IndexedColumns.Add(cpcol);
      cp.Create();

      // Define and XML Index object variable by supplying the parent table and the XML index name arguments in the constructor. 
      Index i;
      i = new Index(tb, "xmlindex");
      IndexedColumn ic;
      ic = new IndexedColumn(i, "XMLValue", true);
      i.IndexedColumns.Add(ic);

      // Create the XML index on the instance of SQL Server. 
      i.Create();
   }
}

Creazione di un indice XML in PowerShell

# Set the path context to the local, default instance of SQL Server and get a reference to adventureworks2012
CD \sql\localhost\default\databases
$db = get-item Adventureworks2012

#Define a Table object variable and add an XML type column. 
#This sample requires that an XML schema type called MySampleCollection exists on the database. 
#See sample on Creating an XML schema to do this
$tb = New-Object -TypeName Microsoft.SqlServer.Management.SMO.Table -argumentlist $db, "XmlTable"
$Type = [Microsoft.SqlServer.Management.SMO.DataType]::Xml("MySampleCollection")
$col1 =  New-Object -TypeName Microsoft.SqlServer.Management.SMO.Column -argumentlist $tb,"XMLValue", $Type
$tb.Columns.Add($col1)

#Add another integer column that can be made into a unique, primary key. 
$Type = [Microsoft.SqlServer.Management.SMO.DataType]::Int
$col2 =  New-Object -TypeName Microsoft.SqlServer.Management.SMO.Column -argumentlist $tb,"Number", $Type
$col2.Nullable = $false
$tb.Columns.Add($col2)
          
#Create the table of the instance of SQL Server. 
$tb.Create()

#Create a unique, clustered, primary key index on the integer column. This is required for an XML index. 
#Define an Index object variable by providing the parent table and index name in the constructor. 
$cp = New-Object -TypeName Microsoft.SqlServer.Management.SMO.Index -argumentlist $tb, "clusprimindex"        
$cp.IsClustered = $true;
$cp.IndexKeyType = [Microsoft.SqlServer.Management.SMO.IndexKeyType]::DriPrimaryKey;

#Create and add an indexed column to the index. 
$cpcol = New-Object -TypeName Microsoft.SqlServer.Management.SMO.IndexedColumn `
-argumentlist $cp, "Number", $true
$cp.IndexedColumns.Add($cpcol)
$cp.Create()

#Define and XML Index object variable by supplying the parent table and
# the XML index name arguments in the constructor. 
$i = New-Object -TypeName Microsoft.SqlServer.Management.SMO.Index -argumentlist $tb, "xmlindex" 

#Create and add an indexed column to the index. 
$ic = New-Object -TypeName Microsoft.SqlServer.Management.SMO.IndexedColumn `
-argumentlist $i, "XMLValue", $true  
$i.IndexedColumns.Add($ic)

#Create the XML index on the instance of SQL Server
$i.Create()

Vedere anche

Riferimento

Index

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