Calling Methods

Straipsnis
04/03/2023

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics

Methods perform specific tasks related to the object, such as issuing a Checkpoint on a database or requesting an enumerated list of logons for the instance of Microsoft SQL Server.

Methods perform an operation on an object. Methods can take parameters and often have a return value. The return value can be a simple data type, a complex object, or a structure that contains many members.

Use exception handling to detect whether the method has been successful. For more information, see Handling SMO Exceptions.

Examples

To use any code example that is provided, you will have to choose the programming environment, the programming template, and the programming language in which to create your application. For more information, see Create a Visual C# SMO Project in Visual Studio .NET.

Using a Simple SMO Method in Visual Basic

In this example, the Create method takes no parameters and has no return value.

'Connect to the local, default instance of SQL Server.
Dim srv As Server
srv = New Server
'Define a Database object variable by supplying the parent server and the database name arguments in the constructor.
Dim db As Database
db = New Database(srv, "Test_SMO_Database")
'Call the Create method to create the database on the instance of SQL Server. 
db.Create()

Using a Simple SMO Method in Visual C#

In this example, the Create method takes no parameters and has no return value.

{   
//Connect to the local, default instance of SQL Server.   
Server srv;   
srv = new Server();   
//Define a Database object variable by supplying the parent server and the database name arguments in the constructor.   
Database db;   
db = new Database(srv, "Test_SMO_Database");   
//Call the Create method to create the database on the instance of SQL Server.   
db.Create();   
}

Using an SMO Method with a Parameter in Visual Basic

The Table object has a method called RebuildIndexes. This method requires a numeric parameter that specifies the FillFactor.

Dim srv As Server  
srv = New Server  
Dim tb As Table  
tb = srv.Databases("AdventureWorks2022").Tables("Employee", "HumanResources")  
tb.RebuildIndexes(70)

Using an SMO Method with a Parameter in Visual C#

The Table object has a method called RebuildIndexes. This method requires a numeric parameter that specifies the FillFactor.

{   
Server srv = default(Server);   
srv = new Server();   
Table tb = default(Table);   
tb = srv.Databases("AdventureWorks2022").Tables("Employee", "HumanResources");   
tb.RebuildIndexes(70);   
}

Using an Enumeration Method that Returns a DataTable Object in Visual Basic

This section describes how to call an enumeration method and how to handle the data in the returned DataTable object.

The EnumCollations method returns a DataTable object, which requires further navigation to access all available collation information about the instance of SQL Server.

'Connect to the local, default instance of SQL Server.  
Dim srv As Server  
srv = New Server  
'Call the EnumCollations method and return collation information to DataTable variable.  
Dim d As DataTable  
'Select the returned data into an array of DataRow.  
d = srv.EnumCollations  
'Iterate through the rows and display collation details for the instance of SQL Server.  
Dim r As DataRow  
Dim c As DataColumn  
For Each r In d.Rows  
    Console.WriteLine("==")  
    For Each c In r.Table.Columns  
        Console.WriteLine(c.ColumnName + " = " + r(c).ToString)  
    Next  
Next

Using an Enumeration Method that Returns a DataTable Object in Visual C#

This section describes how to call an enumeration method and how to handle the data in the returned DataTable object.

The EnumCollations method returns a system DataTable object. The DataTable object requires further navigation to access all available collation information about the instance of SQL Server.

//Connect to the local, default instance of SQL Server.   
{   
Server srv = default(Server);   
srv = new Server();   
//Call the EnumCollations method and return collation information to DataTable variable.   
DataTable d = default(DataTable);   
//Select the returned data into an array of DataRow.   
d = srv.EnumCollations;   
//Iterate through the rows and display collation details for the instance of SQL Server.   
DataRow r = default(DataRow);   
DataColumn c = default(DataColumn);   
foreach ( r in d.Rows) {   
  Console.WriteLine("=========");   
  foreach ( c in r.Table.Columns) {   
    Console.WriteLine(c.ColumnName + " = " + r(c).ToString);   
  }   
}   
}

Constructing an Object in Visual Basic

The constructor of any object can be called by using the New operator. The Database object constructor is overloaded and the version of the Database object constructor that is used in the sample takes two parameters: the parent Server object to which the database belongs, and a string that represents the name of the new database.

'Connect to the local, default instance of SQL Server.
Dim srv As Server
srv = New Server
'Declare and define a Database object by supplying the parent server and the database name arguments in the constructor.
Dim d As Database
d = New Database(srv, "Test_SMO_Database")
'Create the database on the instance of SQL Server.
d.Create()
Console.WriteLine(d.Name)

Constructing an Object in Visual C#

{   
Server srv;   
srv = new Server();   
Table tb;   
tb = srv.Databases("AdventureWorks2022").Tables("Employee", "HumanResources");   
tb.RebuildIndexes(70);   
//Connect to the local, default instance of SQL Server.   
Server srv;   
srv = new Server();   
//Declare and define a Database object by supplying the parent server and the database name arguments in the constructor.   
Database d;   
d = new Database(srv, "Test_SMO_Database");   
//Create the database on the instance of SQL Server.   
d.Create();   
Console.WriteLine(d.Name);   
}

Copying an SMO Object in Visual Basic

This code example uses the Copy method to create a copy of the Server object. The Server object represents a connection to an instance of SQL Server.

'Connect to the local, default instance of SQL Server.
Dim srv1 As Server
srv1 = New Server()
'Modify the default database and the timeout period for the connection.
srv1.ConnectionContext.DatabaseName = "AdventureWorks2022"
srv1.ConnectionContext.ConnectTimeout = 30
'Make a second connection using a copy of the ConnectionContext property and verify settings.
Dim srv2 As Server
srv2 = New Server(srv1.ConnectionContext.Copy)
Console.WriteLine(srv2.ConnectionContext.ConnectTimeout.ToString)

Copying an SMO Object in Visual C#

This code example uses the Copy method to create a copy of the Server object. The Server object represents a connection to an instance of SQL Server.

{   
//Connect to the local, default instance of SQL Server.   
Server srv1;   
srv1 = new Server();   
//Modify the default database and the timeout period for the connection.   
srv1.ConnectionContext.DatabaseName = "AdventureWorks2022";   
srv1.ConnectionContext.ConnectTimeout = 30;   
//Make a second connection using a copy of the ConnectionContext property and verify settings.   
Server srv2;   
srv2 = new Server(srv1.ConnectionContext.Copy);   
Console.WriteLine(srv2.ConnectionContext.ConnectTimeout.ToString);   
}

Monitoring Server Processes in Visual Basic

You can obtain the current status type information about the instance of SQL Server through enumeration methods. The code example uses the EnumProcesses method to discover information about the current processes. It also demonstrates how to work with the columns and rows in the returned DataTable object.

'Connect to the local, default instance of SQL Server.
Dim srv As Server
srv = New Server
'Call the EnumCollations method and return collation information to DataTable variable.
Dim d As DataTable
'Select the returned data into an array of DataRow.
d = srv.EnumProcesses
'Iterate through the rows and display collation details for the instance of SQL Server.
Dim r As DataRow
Dim c As DataColumn
For Each r In d.Rows
    Console.WriteLine("============================================")
    For Each c In r.Table.Columns
        Console.WriteLine(c.ColumnName + " = " + r(c).ToString)
    Next
Next

Monitoring Server Processes in Visual C#

//Connect to the local, default instance of SQL Server.   
{   
Server srv = default(Server);   
srv = new Server();   
//Call the EnumCollations method and return collation information to DataTable variable.   
DataTable d = default(DataTable);   
//Select the returned data into an array of DataRow.   
d = srv.EnumProcesses;   
//Iterate through the rows and display collation details for the instance of SQL Server.   
DataRow r = default(DataRow);   
DataColumn c = default(DataColumn);   
foreach ( r in d.Rows) {   
  Console.WriteLine("=====");   
  foreach ( c in r.Table.Columns) {   
    Console.WriteLine(c.ColumnName + " = " + r(c).ToString);   
  }   
}   
}

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