Re: [ceylon-users] How to create an enum from database column

[Paco Soberón]

Use a switch expression (https://ceylon-lang.org/documentation/1.3/reference/expression/switch/):

case (rs.getString(sex.columnName)) when ("M") m when ("F") F else null

Or, if you are sure about your database contents and don't want to make gender nullable, then:

case (rs.getString(sex.columnName)) when ("M") m else F

El sáb., 7 abr. 2018 20:16, Mohammad Als <karim...@gmail.com> escribió:

If a class is declared with an enum as given

abstract shared class Gender(shared String gender) of m | f {
    string => gender;
}

shared object m extends Gender("M"){}
shared object f extends Gender("F"){}

shared class Person(shared Integer id, shared String firstName, shared String lastName, shared Gender gender) {}

where Gender is an enum.

Then, what is the correct way to write a JDBC row-mapper

shared RowMapper<Person> person_row_mapper = object satisfies RowMapper<Person> {
    shared actual Person map(ResultSet rs) {
        Person person = Person(
            rs.getLong(personId.columnName),
            rs.getString(firstName.columnName),
            rs.getString(lastName.columnName),
            ////object extends Gender( rs.getString(sex.columnName) )   {}
            //this does not work.... because Gender can only be of type m or f   
         );
        return person;
    }
};

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[Paco Soberón]

Sorry, lowercase f:

case (rs.getString(sex.columnName)) when ("M") m when ("F") f else null

case (rs.getString(sex.columnName)) when ("M") m else f