private TableQuery <T> AddOrderBy <U>(Expression <Func <T, U> > orderExpr, bool asc)
{
if (orderExpr.NodeType == ExpressionType.Lambda)
{
LambdaExpression lambda = orderExpr;
MemberExpression mem = null;
UnaryExpression unary = lambda.Body as UnaryExpression;
if (unary != null && unary.NodeType == ExpressionType.Convert)
{
mem = unary.Operand as MemberExpression;
}
else
{
mem = lambda.Body as MemberExpression;
}
if (mem != null && mem.Expression.NodeType == ExpressionType.Parameter)
{
TableQuery <T> q = Clone <T>();
if (q._orderBys == null)
{
q._orderBys = new List <Ordering>();
}
q._orderBys.Add(new Ordering
{
ColumnName = this.Table.FindColumnWithPropertyName(mem.Member.Name).Name,
Ascending = asc
});
return(q);
}
throw new NotSupportedException("Order By does not support: " + orderExpr);
}
throw new NotSupportedException("Must be a predicate");
}
public TableQuery <U> Clone <U>()
{
TableQuery <U> ins = new TableQuery <U>(this._conn, this.Table);
ins._where = _where;
ins._deferred = _deferred;
if (_orderBys != null)
{
ins._orderBys = new List <Ordering>(_orderBys);
}
ins._betweenBy = _betweenBy;
ins._limit = _limit;
ins._offset = _offset;
//Select
ins._selector = _selector;
//Join
ins._joinInner = _joinInner;
ins._joinInnerKeySelector = _joinInnerKeySelector;
ins._joinOuter = _joinOuter;
ins._joinOuterKeySelector = _joinOuterKeySelector;
ins._joinSelector = _joinSelector;
return(ins);
}
public T FirstOrDefault()
{
TableQuery <T> query = Take(1);
return(query.ToList().FirstOrDefault());
}