/// <summary>nothing has been pre-consumed</summary>
/// <returns>null if there is no order by</returns>
/// <exception cref="System.SqlSyntaxErrorException" />
protected internal virtual OrderBy OrderBy()
{
if (lexer.Token() != MySqlToken.KwOrder)
{
return(null);
}
lexer.NextToken();
Match(MySqlToken.KwBy);
var expr = exprParser.Expression();
var order = SortOrder.Asc;
OrderBy orderBy;
switch (lexer.Token())
{
case MySqlToken.KwDesc:
{
order = SortOrder.Desc;
goto case MySqlToken.KwAsc;
}
case MySqlToken.KwAsc:
{
if (lexer.NextToken() != MySqlToken.PuncComma)
{
return(new OrderBy(expr, order));
}
goto case MySqlToken.PuncComma;
}
case MySqlToken.PuncComma:
{
orderBy = new OrderBy();
orderBy.AddOrderByItem(expr, order);
break;
}
default:
{
return(new OrderBy(expr, order));
}
}
for (; lexer.Token() == MySqlToken.PuncComma;)
{
lexer.NextToken();
order = SortOrder.Asc;
expr = exprParser.Expression();
switch (lexer.Token())
{
case MySqlToken.KwDesc:
{
order = SortOrder.Desc;
goto case MySqlToken.KwAsc;
}
case MySqlToken.KwAsc:
{
lexer.NextToken();
break;
}
}
orderBy.AddOrderByItem(expr, order);
}
return(orderBy);
}