private Expression RecursivelyExtractWhereExpression(ParseTreeNode node, Expression p)
{
if (node.Term.Name == "Id")
{
string fieldName = node.ChildNodes[0].Token.Text;
int indexField = SelectClause.IndexOf(fieldName);
if (indexField == -1)
{
throw new NotImplementedException("Use of a field in the WHERE clause without it being present in the SELECT clause is not supported at this time");
}
return(Expression.Convert(
Expression.ArrayAccess(
Expression.Convert(p, typeof(object[])),
Expression.Constant(indexField)),
_Mapping.GetPropertyInfo(FromTable, fieldName).PropertyType));
}
// TODO : all other types should be supported
else if (node.Term.Name == "string")
{
return(Expression.Constant(node.Token.Value.ToString()));
}
else if (node.ChildNodes.Count() == 3)
{
Expression Variable = RecursivelyExtractWhereExpression(node.ChildNodes[0], p);
string Operator = node.ChildNodes[1].ChildNodes[0].Term.Name;
Expression Operand = RecursivelyExtractWhereExpression(node.ChildNodes[2], p);
switch (Operator)
{
case "<": return(Expression.LessThan(Variable, Operand));
case "<=": return(Expression.LessThanOrEqual(Variable, Operand));
case ">": return(Expression.GreaterThan(Variable, Operand));
case ">=": return(Expression.GreaterThanOrEqual(Variable, Operand));
case "=": return(Expression.Equal(Variable, Operand));
case "AND": return(Expression.And(Variable, Operand));
case "OR": return(Expression.Or(Variable, Operand));
default: throw new NotImplementedException(string.Format("{0} is not a supported operator", Operator));
}
}
else
{
throw new BambooException("WHERE clause could not be successfully extracted");
}
}