[odb-users] Null values for unset properties

[Rafael Pena]

I have a class as below. Is there anyway that I can keep the two optional
fields (double optionalValue, string optionalString) as null? If I don't set
the optionValue it defaults to 0 and optionalString defaults to "". I know
the queries can use is_null operator so I am guessing it can be changed
somehow. NOT NULL is the default type in ddl generated by ODB, can I change
the optional fields to #pragma db type("DOUBLE")?  Is there a way to leave
unset fields as null?


#pragma db object
class File {
public:
    File() {
    }
    File(const string& filename);
    File(const File& orig);
    virtual ~File();
//Setters and Getters
private:

    friend class odb::access;
#pragma db id auto
    unsigned long fileId;

    //FileInformation
    string filename;
    string fileType;
    ptime fileDate;
    ptime converterStartdate;
    ptime converterEndDate;
    string loadingHost;
    unsigned long fileSize;


    #pragma db type("DOUBLE")  // Can I do this?
    double optionalValue;
    string optionalString;

};