internal static Expression Parameterize(TableAlias outerAlias, Expression expr)
{
OuterParameterizer op = new OuterParameterizer();
op.outerAlias = outerAlias;
return(op.Visit(expr));
}
/// <summary>
/// Executes the projection.
/// </summary>
/// <param name="projection">The projection.</param>
/// <param name="okayToDefer">if set to <c>true</c> [okay to defer].</param>
/// <returns></returns>
private Expression ExecuteProjection(ProjectionExpression projection, bool okayToDefer)
{
// parameterize query
projection = (ProjectionExpression)this.Parameterize(projection);
if (this.scope != null)
{
// also convert references to outer alias to named values! these become SQL parameters too
projection = (ProjectionExpression)OuterParameterizer.Parameterize(this.scope.Alias, projection);
}
FixColumnNames(projection);
string commandText = this.linguist.Format(projection.Select);
ReadOnlyCollection <NamedValueExpression> namedValues = NamedValueGatherer.Gather(projection.Select);
QueryCommand command = new QueryCommand(commandText, namedValues.Select(v => new QueryParameter(v.Name, v.Type)));
Expression[] values = namedValues.Select(v => Expression.Convert(this.Visit(v.Value), typeof(object))).ToArray();
return(this.ExecuteProjection(projection, okayToDefer, command, values));
}