/// <summary>
/// Creates a new <see cref="KCommandQuery"/> instance associated with this link object, and sets the initial
/// contents of the From clause by parsing the command object given, and associating it to a given alias.
/// </summary>
/// <param name="link">The link the comand will be associated to.</param>
/// <param name="command">The command object.</param>
/// <param name="alias">The alias.</param>
/// <returns>The new created command.</returns>
public static KCommandQuery From( this IKLink link, IKCommand command, Func<dynamic, object> alias )
{
var cmd = link.Query().From( command, alias );
return cmd;
}
/// <summary>
/// Appends to the Select clause the contents obtained by parsing the command object given, and associating
/// it to a given alias.
/// </summary>
/// <param name="command">The command object.</param>
/// <param name="alias">The alias.</param>
/// <returns>This command, to allow it to permit it to be used in a fluent syntax fashion.</returns>
public virtual KCommandQuery Select( IKCommand command, Func<dynamic, object> alias )
{
if( command == null ) throw new ArgumentNullException( "command", "Command specification cannot be null." );
if( alias == null ) throw new ArgumentNullException( "alias", "Alias specification cannot be null." );
string main = Parser.Parse( command, pars: Parameters );
string nick = Parser.Parse( alias );
nick = nick.Validated( "Alias", invalidChars: TypeHelper.InvalidNameChars );
string str = string.Format( "( {0} ) AS {1}", main, nick );
_TextSelect = _TextSelect == null
? string.Format( "{0}", str )
: string.Format( "{0}, {1}", _TextSelect, str );
return this;
}
internal KSurrogate( IKCommand command, bool iterable )
{
DEBUG.IndentLine( "\n-- KSurrogate( Iterable={0}, Command={1} )", iterable, command == null ? "null" : command.ToString() );
if( ( _Command = command ) == null ) throw new ArgumentNullException( "command", "Command cannot be null." );
if( _Command.Link == null ) throw new ArgumentException( "Command's link is null." );
_Link = _Command.Link as KLinkDirect; if( _Link == null ) throw new ArgumentException( "Command's link is not a direct link." );
Invoke( iterable );
DEBUG.Unindent();
}
protected virtual void Dispose( bool disposing )
{
DEBUG.IndentLine( "\n-- KSurrogate.Dispose( Disposing={0} ) - This={1}", disposing, this );
if( _DataReader != null ) {
if( !_DataReader.IsClosed ) _DataReader.Close();
_DataReader.Dispose();
_DataReader = null;
}
if( _Link != null ) {
if( _LinkOpenedBySurrogate ) _Link.DbClose();
_Link = null;
}
_Schema = null; // It might be in use elsewhere
_Command = null;
DEBUG.Unindent();
}
protected virtual string ParseCommand( IKCommand node, KParameterList pars = null )
{
// Getting the command's text...
string str = node.CommandText( iterable: false ); // Avoiding spurious "OUTPUT XXX" statements
// If there are parameters to transform, but cannot store them, it is an error
if( node.Parameters.Count != 0 && pars == null )
throw new InvalidOperationException( "Cannot parse IKCommand because the receiving parameters collection is null." );
// Transforming the parameters using names compatible with this command string and context
foreach( var parameter in node.Parameters ) {
KParameter neo = pars.Insert( parameter.Value );
str = str.Replace( parameter.Name, neo.Name );
}
return str;
}
