SqlCeCommand Class

Represents an SQL statement to execute against a data source.

Inheritance Hierarchy

System.Object
  System.MarshalByRefObject
    System.ComponentModel.Component
      System.Data.Common.DbCommand
        System.Data.SqlServerCe.SqlCeCommand

Namespace:  System.Data.SqlServerCe
Assembly:  System.Data.SqlServerCe (in System.Data.SqlServerCe.dll)

Syntax

'Declaration
Public NotInheritable Class SqlCeCommand _
    Inherits DbCommand _
    Implements ICloneable
'Usage
Dim instance As SqlCeCommand

public sealed class SqlCeCommand : DbCommand, 
    ICloneable

public ref class SqlCeCommand sealed : public DbCommand, 
    ICloneable

[<SealedAttribute>]
type SqlCeCommand =  
    class
        inherit DbCommand
        interface ICloneable
    end

public final class SqlCeCommand extends DbCommand implements ICloneable

The SqlCeCommand type exposes the following members.

Constructors

	Name	Description
	SqlCeCommand()	Initializes a new instance of the SqlCeCommand class.
	SqlCeCommand(String)	Initializes a new instance of the SqlCeCommand class with the text of the query.
	SqlCeCommand(String, SqlCeConnection)	Initializes a new instance of the SqlCeCommand class with the text of the query and a SqlCeConnection.
	SqlCeCommand(String, SqlCeConnection, SqlCeTransaction)	Initializes a new instance of the SqlCeCommand class with the text of the query, a SqlCeConnection, and the SqlCeTransaction.

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Properties

	Name	Description
	CanRaiseEvents	(inherited from Component)
	CommandText	Gets or sets an SQL statement to execute at the data source. (Overrides DbCommand.CommandText.)
	CommandTimeout	Gets or sets the wait time before terminating the attempt to execute a command and generating an error. (Overrides DbCommand.CommandTimeout.)
	CommandType	Gets or sets a value indicating how the CommandText property is interpreted. (Overrides DbCommand.CommandType.)
	Connection	Gets or sets the SqlCeConnection used by this instance of the SqlCeCommand.
	Container	(inherited from Component)
	DbConnection	(inherited from DbCommand)
	DbParameterCollection	(inherited from DbCommand)
	DbTransaction	(inherited from DbCommand)
	DesignMode	(inherited from Component)
	DesignTimeVisible	Get always returns false; set always throws a NotSupportedException. (Overrides DbCommand.DesignTimeVisible.)
	Events	(inherited from Component)
	IndexName	Specifies the index to be opened.
	Parameters	Gets the SqlCeParameterCollection.
	Site	(inherited from Component)
	Transaction	Gets or sets the transaction in which the SqlCeCommand executes.
	UpdatedRowSource	Gets or sets how command results are applied to the DataRow when used by the Update method of the DbDataAdapter. This property should not be used with the .NET Compact Framework Data Provider for SQL Server Compact. (Overrides DbCommand.UpdatedRowSource.)

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Methods

	Name	Description
	Cancel	Attempts to cancel the execution of a SqlCeCommand. (Overrides DbCommand.Cancel().)
	CreateDbParameter	(inherited from DbCommand)
	CreateObjRef	(inherited from MarshalByRefObject)
	CreateParameter	Creates a new instance of a SqlCeParameter object.
	Dispose()	(inherited from Component)
	Dispose(Boolean)	(inherited from Component)
	Equals	(inherited from Object)
	ExecuteDbDataReader	(inherited from DbCommand)
	ExecuteNonQuery	Executes an SQL statement against the SqlCeConnection and returns the number of rows affected. (Overrides DbCommand.ExecuteNonQuery().)
	ExecuteReader()	Sends the CommandText to the Connection and builds a SqlCeDataReader.
	ExecuteReader(CommandBehavior)	Sends the CommandText to the Connection and builds a SqlCeDataReader by using one of the CommandBehavior values.
	ExecuteResultSet(ResultSetOptions)	Sends the CommandText to the Connection and builds a SqlCeResultSet by using the ResultSetOptions.
	ExecuteResultSet(ResultSetOptions, SqlCeResultSet)	Sends the CommandText to the Connection and builds a SqlCeResultSet by using the ResultSetOptions.
	ExecuteScalar	Executes the query and returns the first column of the first row in the result set that is returned by the query. Extra columns or rows are ignored. (Overrides DbCommand.ExecuteScalar().)
	Finalize	(inherited from Component)
	GetHashCode	(inherited from Object)
	GetLifetimeService	(inherited from MarshalByRefObject)
	GetService	(inherited from Component)
	GetType	(inherited from Object)
	InitializeLifetimeService	(inherited from MarshalByRefObject)
	MemberwiseClone()	(inherited from Object)
	MemberwiseClone(Boolean)	(inherited from MarshalByRefObject)
	Prepare	Creates a prepared (or compiled) version of the command on the data source. (Overrides DbCommand.Prepare().)
	SetRange	Restricts the set of rows that will be read by the SqlCeDataReader.
	ToString	(inherited from Component)

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Events

	Name	Description
	Disposed	(inherited from Component)

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Explicit Interface Implementations

	Name	Description
	ICloneable.Clone
	IDbCommand.Connection	(inherited from DbCommand)
	IDbCommand.CreateParameter	(inherited from DbCommand)
	IDbCommand.ExecuteReader()	(inherited from DbCommand)
	IDbCommand.ExecuteReader(CommandBehavior)	(inherited from DbCommand)
	IDbCommand.Parameters	(inherited from DbCommand)
	IDbCommand.Transaction	(inherited from DbCommand)

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Remarks

When an instance of SqlCeCommand is created, the read/write properties are set to their initial values. For a list of these values, see the SqlCeCommand constructor.

SqlCeCommand features the following methods that execute commands at a data source:

Item	Description
ExecuteReader	Executes commands that return rows.
ExecuteNonQuery	Executes SQL commands such as INSERT, DELETE, and UPDATE statements.
ExecuteScalar	Retrieves a single value (for example, an aggregate value) from a database.
ExecuteResultSet	Executes commands and returns a result set.

The Data Provider for SQL Server Compact does not support batched queries. Commands must be in the following form:

Select * from Customers and not Select * from Customers; Select * from Orders;

If you are using code generated for System.Data.SqlClient, you may have to alter your queries to conform to this restriction.

SQL Server Compact supports multiple simultaneous connections as well as multiple commands sharing the same connection. This means that it is possible to have multiple instances of SqlCeDataReader on the same connection. This behavior differs from that of System.Data.SqlClient.

If a fatal SqlCeException is generated by the method executing a SqlCeCommand, the SqlCeConnection may be closed. You can reopen the connection and continue.

Examples

The following example uses SqlCeCommand, along with SqlCeConnection, to select rows from a database.

Dim query As String = "SELECT [Order ID], [Customer] FROM Orders"
Dim conn As New SqlCeConnection(connString)
Dim cmd As New SqlCeCommand(query, conn)

conn.Open()
Dim rdr As SqlCeDataReader = cmd.ExecuteReader()

Try
    ' Iterate through the results
    '
    While rdr.Read()
        Dim val1 As Integer = rdr.GetInt32(0)
        Dim val2 As String = rdr.GetString(1)
    End While
Finally
    ' Always call Close when done reading
    '
    rdr.Close()

    ' Always call Close when done reading
    '
    conn.Close()
End Try

string query = "SELECT [Order ID], [Customer] FROM Orders";
SqlCeConnection conn = new SqlCeConnection(connString);
SqlCeCommand cmd = new SqlCeCommand(query, conn);

conn.Open();
SqlCeDataReader rdr = cmd.ExecuteReader();

try
{
    // Iterate through the results
    //
    while (rdr.Read())
    {
        int val1 = rdr.GetInt32(0);
        string val2 = rdr.GetString(1);
    }
}
finally
{
    // Always call Close when done reading
    //
    rdr.Close();

    // Always call Close when done reading
    //
    conn.Close();
}

Thread Safety

Any public static (Shared in Microsoft Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference

System.Data.SqlServerCe Namespace

SqlCeDataAdapter

SqlCeConnection