使用枚举属性作为ormlite列值，而不是序号。可能吗？ [英] Using enum property as ormlite column value instead of ordinal. is it possible?
问题描述
@DatabaseField(dataType=DataType.ENUM_STRING,columnName=TIPO_FIELD_NAME)
private TipoPedido tipo;
public enum TipoPedido {
REGISTARNOTIFICACAORESPOSTA("Registar Notificação Resposta",SIGLA_TIPO_REGISTARNOTIFICATIORESPOSTA);
private String tipoName;
private String tipoValue;
TipoPedido(String tipoName,String tipoValue){
this.tipoName=tipoName;
this.tipoValue=tipoValue;
}
public String getTipoName(){
return tipoName;
}
public String getTipoValue(){
return tipoValue;
}
}
是否有可能使用tipoValue枚举属性作为值的列代替序号
Is it possible to use the tipoValue enum property as the value for the column instead of the ordinal?
编辑：这里就是我所做的：
here's what i did:
创建了MyEnumPersister类：
Created the MyEnumPersister class:
public class MyEnumPersister extends EnumStringType{
private static final MyEnumPersister singleTon = new MyEnumPersister();
/**
* @param sqlType
* @param classes
*/
protected MyEnumPersister() {
super(SqlType.STRING, new Class<?>[] { Enum.class });
}
public static MyEnumPersister getSingleton() {
return singleTon;
}
@Override
public Object javaToSqlArg(FieldType fieldType, Object obj) {
return ((EstadoPedido)obj).getEstadoValue();
}
@Override
public Object sqlArgToJava(FieldType fieldType, Object sqlArg, int columnPos)
throws SQLException {
return PedidoDTO.siglaEstadoPedidoComparator((String)sqlArg);
}
}
在javatoSqlArg我直接返回通过使用枚举内的吸气剂对应于estadoValue字符串。
我想从数据库中，我将需要实现sqlArgToJava方法太拿回来一个枚举，但我还没有建立它。
In javatoSqlArg i return directly the string corresponding to the estadoValue by using the getter inside the Enum. I assume to get it back to a Enum from the DataBase i will need to implement the sqlArgToJava method too, but i'm yet to build it.
EDIT2：看来，当我做保存数据，方法javaToSqlArg得到的sqlArgToJava之前调用表的查询，为什么？这里的查询：
edit2: Seems that when i do a query on the table that holds the data, the method javaToSqlArg gets called before the sqlArgToJava, why??? here's the query:
public List<PedidoDTO> getPendingRequests(){
List<PedidoDTO> pendingReq=null;
QueryBuilder<PedidoDTO, Integer> queryBuild=null;
try {
queryBuild=getHelper().getPedidosDao().queryBuilder();
pendingReq=queryBuild.where().eq(PedidoDTO.ESTADO_FIELD_NAME, PedidoDTO.SIGLA_ESTADO_PENDENTE).query();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return pendingReq;
}
obj的值显示为这是我转换成SQL时我在数据库中插入为P。犯规什么太大的意义......
The obj value appears as "P" which was what i convert to sql when i inserted it in the Database. Doesnt make too much sense....
推荐答案
默认情况下ORMLite存储枚举类型的字符串名称 - 在你的情况下，将存储 REGISTARNOTIFICACAORESPOSTA 。您可以覆盖此行为，并通过 ENUM_INTEGER 数据类型存储序号值：
By default ORMLite stores the string name of the enumerated type -- in your case it would store REGISTARNOTIFICACAORESPOSTA. You can override this behavior and store the ordinal value by using the ENUM_INTEGER data-type:
@DatabaseField(dataType=DataType.ENUM_INTEGER)
private TipoPedido tipo;
这将存储整数数据库而不是字符串序号值。引用文档：
This will store the integer ordinal value in the database instead of the string. To quote the docs:
字符串名称是默认（和建议在 ENUM_INTEGER ），因为它可以让你在列表中的任意位置添加额外的枚举，而不必担心数据后进行转换。
The string name is the default (and recommended over
ENUM_INTEGER) because it allows you to add additional enums anywhere in the list without worrying about having to convert data later.
不过，好像你要存储从枚举的 tipoValue 字符串而不是。要做到这一点，你正在做的有，而不是注册自定义持留。查看有关此文档：
However, it seems like you want to store the tipoValue string from the enum instead. To do this you are doing to have to register a custom persister instead. See the docs about this:
http://ormlite.com/docs/custom-persister
这让你想如何在Java领域转化为数据库重新presentation您具体界定，反之亦然。这两种重要的方法是：
This allows you to define specifically how you want to translate the Java field into the database representation, and vice versa. The two important methods are:
-
javaToSqlArg（...）它从Java转换成数据库格式和 -
sqlArgToJava（...）从数据库转换回Java的。
您可以延长 BaseDataType 并建立从地面转换器或可以扩展的 EnumStringType 或的 StringType ，只是覆盖上面的重要方法。
You can extend BaseDataType and build the converter from the ground up or you can extend EnumStringType or StringType and just override the above important methods.
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