Column.IsPersisted 속성
Gets the Boolean property value that specifies whether the computed value of the Column object is saved with the data, thus avoiding a computation each time the column is accessed.
네임스페이스: Microsoft.SqlServer.Management.Smo
어셈블리: Microsoft.SqlServer.Smo(Microsoft.SqlServer.Smo.dll)
구문
‘선언
<SfcPropertyAttribute(SfcPropertyFlags.None Or SfcPropertyFlags.Standalone Or SfcPropertyFlags.SqlAzureDatabase Or SfcPropertyFlags.Design)> _
Public Property IsPersisted As Boolean
Get
Set
‘사용 방법
Dim instance As Column
Dim value As Boolean
value = instance.IsPersisted
instance.IsPersisted = value
[SfcPropertyAttribute(SfcPropertyFlags.None|SfcPropertyFlags.Standalone|SfcPropertyFlags.SqlAzureDatabase|SfcPropertyFlags.Design)]
public bool IsPersisted { get; set; }
[SfcPropertyAttribute(SfcPropertyFlags::None|SfcPropertyFlags::Standalone|SfcPropertyFlags::SqlAzureDatabase|SfcPropertyFlags::Design)]
public:
property bool IsPersisted {
bool get ();
void set (bool value);
}
[<SfcPropertyAttribute(SfcPropertyFlags.None|SfcPropertyFlags.Standalone|SfcPropertyFlags.SqlAzureDatabase|SfcPropertyFlags.Design)>]
member IsPersisted : bool with get, set
function get IsPersisted () : boolean
function set IsPersisted (value : boolean)
속성 값
유형: System.Boolean
A Boolean property value that specifies whether the computed value of the Column object is saved with the data.If True, the computed value of the Column object is saved with the data.If False (default), the computed value of the Column object is computed every time the column data is requested. The IsPersisted property can only be set to True for computed columns. Otherwise, it will cause an error.
주의
The following example shows how to use feature in C#:
// compile with: /r:Microsoft.SqlServer.Smo.dll /r:Microsoft.SqlServer.ConnectionInfo.dll /r:Microsoft.SqlServer.Management.Sdk.Sfc.dll
using System;
using Microsoft.SqlServer.Management.Smo;
public class A {
public static void Main() {
Server svr = new Server();
Database db = new Database(svr, "TestDB");
db.Create();
Table tab1 = new Table(db, "Table1");
Column col1 = new Column(tab1, "Col1", DataType.Int);
// Computed column
Column col2 = new Column(tab1, "Col2", DataType.Int);
col2.Computed = true;
col2.ComputedText = "col1 * 2";
// Persisted Computed Column
Column col3 = new Column(tab1, "Col3", DataType.Int);
col3.Computed = true;
col3.ComputedText = "col1 * 3";
// allows the computed column to persist with table data
col3.IsPersisted = true;
tab1.Columns.Add(col1);
tab1.Columns.Add(col2);
tab1.Columns.Add(col3);
tab1.Create();
// default value of IsPersisted for computed column is false
Console.WriteLine(col2.Name + " Computed = " + col2.Computed + " Persisted = " + col2.IsPersisted);
Console.WriteLine(col3.Name + " Computed = " + col3.Computed + " Persisted = " + col3.IsPersisted);
}
}
The following example shows how to use feature in Visual Basic:
' compile with: /r:Microsoft.SqlServer.Smo.dll /r:Microsoft.SqlServer.ConnectionInfo.dll /r:Microsoft.SqlServer.Management.Sdk.Sfc.dll
Imports Microsoft.SqlServer.Management.Smo
Public Class A
Public Shared Sub Main()
Dim svr As New Server()
Dim db As New Database(svr, "TestDB")
db.Create()
Dim tab1 As New Table(db, "Table1")
Dim col1 As New Column(tab1, "Col1", DataType.Int)
' Computed column
Dim col2 As New Column(tab1, "Col2", DataType.Int)
col2.Computed = True
col2.ComputedText = "col1 * 2"
' Persisted Computed Column
Dim col3 As New Column(tab1, "Col3", DataType.Int)
col3.Computed = True
col3.ComputedText = "col1 * 3"
' allows the computed column to persist with table data
col3.IsPersisted = True
tab1.Columns.Add(col1)
tab1.Columns.Add(col2)
tab1.Columns.Add(col3)
tab1.Create()
' default value of IsPersisted for computed column is false
Console.WriteLine((col2.Name & " Computed = " & col2.Computed & " Persisted = ") & col2.IsPersisted)
Console.WriteLine((col3.Name & " Computed = " & col3.Computed & " Persisted = ") & col3.IsPersisted)
End Sub
End Class
참고 항목
참조
Microsoft.SqlServer.Management.Smo 네임스페이스