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How to update NOT NULL values ​​when writing data to Realm

Hello to all! My scenario is that I have a screen with a feed, and every element of the feed with its details is stored in the kingdom. Each of these elements has offset and feedPostedAt properties. A problem occurs when the user clicks on an item and the part part is loaded to provide current data. However, the loaded part does not contain the property offset and feedPostedAt, so when I update in the ( realm.copyOrUpdate () ) area, this element will overwrite the old element with the offset and feedPostedAt properties set.

Is there a way that a scope updates only the values ​​that are defined and leaves properties with NULL values ​​intact?

Now I deal with this problem so that I manually reset the offset and the feedPostedAt property, but this is not nice and efficient.

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It may be a little late, but this is what I use. This method updates the base object with non-default properties of the update object. Then, the Realm#insertOrUpdate method is used to update the area database.

  /** * Both classes must be detached from realm. * Primitives compared with their defaults. * check <a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.12.5"/>default values of primitives</> */ public static <T> void updateObject(T base, T update) { Class<?> aClass = base.getClass(); for (Field field : aClass.getDeclaredFields()) { try { field.setAccessible(true); Class<?> fieldType = field.getType(); if (fieldType.isPrimitive()) { if (fieldType.equals(boolean.class)) { if (field.getBoolean(update)) { field.setBoolean(base, true); } } else if (fieldType.equals(int.class)) { if (field.getInt(update) != 0) { field.setInt(base, field.getInt(update)); } } else if (fieldType.equals(long.class)) { if (field.getLong(update) != 0L) { field.setLong(base, field.getLong(update)); } } else if (fieldType.equals(short.class)) { if (field.getShort(update) != (short) 0) { field.setShort(base, field.getShort(update)); } } else if (fieldType.equals(byte.class)) { if (field.getByte(update) != (byte) 0) { field.setByte(base, field.getByte(update)); } } else if (fieldType.equals(float.class)) { if (field.getFloat(update) != 0.0f) { field.setFloat(base, field.getFloat(update)); } } else if (fieldType.equals(double.class)) { if (field.getDouble(update) != 0.0d) { field.setDouble(base, field.getDouble(update)); } } else if (fieldType.equals(char.class)) { if (field.getChar(update) != '\u0000') { field.setChar(base, field.getChar(update)); } } } else { Object newValue = field.get(update); if (newValue != null) { field.set(base, newValue); } } } catch (IllegalAccessException e) { e.printStackTrace(); } } }
  • It uses reflection to access all properties.
  • Both objects should be separated from the area.
  • The object model must have the @PrimaryKey annotated property in Realm#insertOrUpdate order to do its job. Otherwise, the method requires some configuration.
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