在升级我的数据库架构时,我遇到了 ForeignCollectionField (ormlite 4.7) 不返回行的问题。通过全新安装应用程序,可以按预期添加和显示行。
当应用程序更新到新版本时,架构会更新(见下文),但是当将行添加到数据库时,集合不会返回添加的行。(我可以看到数据库中存在这些行)
父行在更新之前存在。我需要做什么来修复它?
定义了外部集合的父类
@DatabaseTable(tableName = "setting")
public class SettingEntity {
@DatabaseField(generatedId = true)
private long id;
…
//New field added
@ForeignCollectionField
private ForeignCollection<DistributionEntity> distribution;
public SettingEntity() {
// Required for ORMLite
}
public ForeignCollection<DistributionEntity> getDistribution() {
return distribution;
}
public void setDistribution(ForeignCollection<DistributionEntity> distribution) {
this.distribution = distribution;
}
}
儿童班
@DatabaseTable(tableName = "distribution")
public class DistributionEntity {
@DatabaseField(generatedId = true)
private long id;
…
//New field added
@DatabaseField(canBeNull = true, foreign = true, index = true, foreignAutoRefresh = true, columnDefinition = "integer references setting(id) on delete cascade")
private SettingEntity setting;
public void setSetting(SettingEntity setting) {
this.setting = setting;
}
}
onUpgrade 代码
RuntimeExceptionDao<DistributionEntity, Integer> distributionDao = helper.getDistributionDao();
distributionDao.executeRaw("ALTER TABLE distribution ADD setting_id");
distributionDao.executeRaw("CREATE INDEX distribution_setting_idx ON distribution (setting_id)");
ForeignCollectionField 调用分布的调试信息
遍历集合的代码
public ArrayList<Distribution> getDistribution() {
getEntity().getDistribution().size();
final ArrayList<Distribution> items = new ArrayList<Distribution>();
final ForeignCollection<DistributionEntity> collection = getEntity().getDistribution();
for (final DistributionEntity item : collection) {
final Distribution dist = new Distribution(item, mContext);
items.add(dist);
}
return items;
}
注意 getEntity() 返回 SettingEntity 的实例
感谢您花时间