迁移到会议室:如何进行全文搜索? [英] Migrating to Room: How to do Full Text Search?

问题描述

我一直在寻找如何将现有的应用程序从普通的Sqlite迁移到Room的方法，但是我一直无法找到如何迁移使用FTS的部件的方法.

I was looking how to migrate an existing application to Room, from plain Sqlite, and I haven't been able to find how could I migrate a part that uses FTS.

现在，我有一个虚拟表，每次插入或更新一行时，触发器都会填充该表:

Right now, I have a virtual table that's filled by a trigger every time a row is inserted or updated:

private static final String CREATE_VIRTUAL_TABLE = "CREATE VIRTUAL TABLE " + FTS_VIRTUAL_TABLE +
            " using fts4 (content='" + TABLE_NOTIFICATION + "', " + COLUMN_TITLE + ")";

private static void createVirtualTriggers(SQLiteDatabase database){
      database.execSQL("CREATE TRIGGER virtual_bu BEFORE UPDATE ON " + TABLE_NOTIFICATION + " BEGIN\n" +  "  DELETE FROM " + FTS_VIRTUAL_TABLE + " WHERE docid=old.rowid;\n" +    "END;");
      database.execSQL("CREATE TRIGGER virtual_bd BEFORE DELETE ON " + TABLE_NOTIFICATION + " BEGIN\n" +  "  DELETE FROM " + FTS_VIRTUAL_TABLE + " WHERE docid=old.rowid;\n" +    "END;");
      database.execSQL("CREATE TRIGGER virtual_au AFTER UPDATE ON " + TABLE_NOTIFICATION + " BEGIN\n" +  "  INSERT INTO " + FTS_VIRTUAL_TABLE + "(docid, " + COLUMN_TITLE + ") VALUES(new.rowid, new." + COLUMN_TITLE +");\n" + "END;");
      database.execSQL("CREATE TRIGGER virtual_ai AFTER INSERT ON " + TABLE_NOTIFICATION + " BEGIN\n" +  "  INSERT INTO " + FTS_VIRTUAL_TABLE + "(docid, " + COLUMN_TITLE + ") VALUES(new.rowid, new." + COLUMN_TITLE +");\n" +                   "END;");
  }

有什么办法可以通过Room实现相同的功能吗?

Is there any way to achieve this same functionality with Room?

推荐答案

不是.请参见此问题和

Not really. See this issue and this issue where this request is being tracked.

您始终可以直接针对FTS场景使用数据库，例如通过

You can always work with the database directly for FTS scenarios, such as creating the table and triggers in your code snippet in the question, by calling getOpenHelper() on the RoomDatabase and using it similar to SQLiteOpenHelper. Room will ignore new tables and stuff that you create behind its back. So, if your FTS work happens to be fairly separate from the rest of your database work, you might be able to go that route.

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