public expression(Ioperand ol, comparisonoperator _opdef, Ioperand or)
{
/* binary operation */
operand_l = ol;
opdef = _opdef;
operand_r = or;
}
public Ioperand operand_r; /* null for non-binary operators */
public expression(Ioperand ol, comparisonoperator _opdef)
{
/* unary: only limited subset of possible operators */
switch (_opdef)
{
case comparisonoperator.coIsnull:
case comparisonoperator.coNotnull:
case comparisonoperator.coHastext:
case comparisonoperator.coHasNoText:
case comparisonoperator.coExists:
case comparisonoperator.coNotExists:
break;
default:
throw new ArgumentOutOfRangeException(String.Format("_opdef '{0}' asks for two operands", _opdef.ToString()));
}
operand_l = ol;
opdef = _opdef;
/* [rzamponi 20100112] FxCop CA1805:DoNotInitializeUnnecessarily */
//operand_r = null;
}
public static Iexpressionlistitem where_fld_op(string tablealias1, string fieldname1, comparisonoperator op, string tablealias2, string fieldname2)
{
return(new expression(new operand(new selectfield(tablealias1, fieldname1)), op, new operand(new selectfield(tablealias2, fieldname2))));
}
public static Iexpressionlistitem where_fld_op_p(string fieldname, comparisonoperator op, string paramname, DbType paramtype)
{
return(new expression(new operand(fieldname), op, new param(new selectparam(paramname, paramtype))));
}
public static Iexpressionlistitem where_fld_op_subquery(string tablealias, string fieldname, comparisonoperator op, subquery in_subquery)
{
return(new expression(new operand(new selectfield(tablealias, fieldname)), op, new operand(new selectfield(in_subquery, null))));
}
