ICode ResolveExpressionObject(Expression exp)
{
object obj;
if (!ExpressionToObject.GetExpressionObject(exp, out obj))
{
throw new NotSupportedException();
}
//object symbol.
//for example enum.
var symbol = exp.Type.GetObjectConverter();
if (symbol != null)
{
return(symbol.Convert(obj));
}
//IDbParam.
if (typeof(IDbParam).IsAssignableFromEx(exp.Type))
{
string name = string.Empty;
MetaId metaId = null;
var member = exp as MemberExpression;
if (member != null)
{
name = member.Member.Name;
metaId = new MetaId(member.Member);
}
var param = obj as IDbParam;
//use field name.
return(new ParameterCode(name, metaId, param));
}
//sql.
//example [ IN(exp) ]
var sqlExp = obj as Sql;
if (sqlExp != null)
{
Type type = null;
var types = sqlExp.GetType().GetGenericArgumentsEx();
if (0 < types.Length)
{
type = types[0];
}
return(SqlCode.Create(sqlExp.Code));
}
//others.
//Even if it is not a supported type, if it is correctly written it will be cast to the caller.
{
string name = string.Empty;
MetaId metaId = null;
var member = exp as MemberExpression;
if (member != null)
{
name = member.Member.Name;
metaId = new MetaId(member.Member);
}
//use field name.
return(new ParameterCode(name, metaId, new DbParamValueOnly()
{
Value = obj
}));
}
}
