internal SelectExpression(LambdaExpression projection, FromExpression from, WhereExpression where, string alias, bool isProjection, Expression take, OrderByClause orderBy)
: base(CompleteExpressionType.Select, typeof(IEnumerable<>).MakeGenericType(projection.ReturnType))
{
this.Projection = projection;
this.Alias = alias;
this.From = from;
this.Where = where;
this.Take = take;
this.OrderBy = orderBy;
this.IsProjection = isProjection;
var ce = ColumnExtractor.ExtractColumns(this, projection);
this._Columns = ce.Columns.ToList();
this._Assignments = ce.Assignments.ToList();
}
protected virtual Expression VisitWhere(WhereExpression where)
{
this.Write(".Where(");
this.WriteLine(Indentation.Inner);
this.Visit(where.Predicate);
this.WriteLine(Indentation.Outer);
this.Write(")");
return where;
}
internal WhereExpression(Expression predicate, WhereExpression previousWhere)
: base(CompleteExpressionType.Where, typeof(bool))
{
if (predicate == null) throw new ArgumentNullException("predicate");
if (predicate.Type != typeof(bool))
throw new ArgumentException("'predicate' must return a bool.", "predicate");
if (previousWhere != null)
{
predicate =
Expression.AndAlso(
predicate,
previousWhere.Predicate);
}
this.Predicate = predicate;
}
protected virtual Expression VisitWhere(WhereExpression where)
{
var predicate = this.Visit(where.Predicate);
if (predicate == where.Predicate)
return where;
return CompleteExpression.Where(predicate);
}
protected override Expression VisitWhere(WhereExpression where)
{
sb.Append("where ");
if (where.Predicate is BinaryExpression)
this.Visit(where.Predicate);
else if (where.Predicate.NodeType == ExpressionType.Constant)
{
var value = (bool)((where.Predicate as ConstantExpression).Value);
if (value)
sb.Append("1 = 1");
else
sb.Append("0 = 1");
}
else if (where.Predicate is ConditionalExpression)
{
this.Visit(where.Predicate);
sb.Append(" = 1");
}
else
throw new NotSupportedException("Not sure yet what to do here. ");
this.AppendNewLine(Indentation.Same);
return where;
}
public static WhereExpression Where(Expression predicate, WhereExpression previousWhere = null)
{
return new WhereExpression(predicate, previousWhere);
}
public static SelectExpression Select(string alias, LambdaExpression projection, FromExpression from, OrderByClause orderBy, WhereExpression where = null, bool isProjection = true, Expression take = null)
{
return new SelectExpression(projection, from, where, alias, isProjection, take, orderBy);
}
