如何实现Android Sqlite Union rawQuery？

我正在使用以下代码来搜索“英文”列。还有另一个栏目叫做“BANGLA”。我应该如何修改代码，以便同时搜索“ENGLISH”和“BANGLA”列并作为组合结果返回？如何实现Android Sqlite Union rawQuery？

public List<Bean> getWords(String englishWord) { 
     if(englishWord.equals("")) 
      return new ArrayList<Bean>(); 

     String sql = "SELECT * FROM " + TABLE_NAME + 
       " WHERE " + ENGLISH + " LIKE ? ORDER BY " + ENGLISH + " LIMIT 100 "; 

     SQLiteDatabase db = initializer.getReadableDatabase(); 

     Cursor cursor = null; 
     try { 
      cursor = db.rawQuery(sql, new String[]{"%" + englishWord + "%"}); 

      List<Bean> wordList = new ArrayList<Bean>(); 
      while(cursor.moveToNext()) { 
       int id = cursor.getInt(0); 
       String english = cursor.getString(1); 
       String bangla = cursor.getString(2); 
       String status = cursor.getString(3); 
       wordList.add(new Bean(id, english, bangla, status)); 
      } 

      return wordList; 
     } catch (SQLiteException exception) { 
      exception.printStackTrace(); 
      return null; 
     } finally { 
      if (cursor != null) 
       cursor.close(); 
     } 
    }

我体改的String sql到

String sql = "SELECT * FROM " + TABLE_NAME + 
       " WHERE " + ENGLISH + " LIKE ? ORDER BY " + ENGLISH + " LIMIT 100 " + " UNION ALL " + " SELECT * FROM " + TABLE_NAME + 
       " WHERE " + BANGLA + " LIKE ? ORDER BY " + ENGLISH + " LIMIT 100";

但是，这是行不通的。我收到此错误：

ORDER BY clause should come after UNION ALL not before (code 1): , while compiling: SELECT * FROM words WHERE en_word LIKE ? ORDER BY en_word LIMIT 100 UNION ALL SELECT * FROM words WHERE bn_word LIKE ? ORDER BY en_word LIMIT 100

来源

2015-09-27 user2872856

这不起作用？ – e4c5

你得到了什么确切的错误？难道你没有添加第二个选择参数？ 'cursor = db.rawQuery（sql，new String [] {“％”+ englishWord +“％”，“％”+ englishWord +“％”}）;' – jyanks

我越来越'wordList == null 。我按照建议添加了第二个选择参数，但仍然无效。 – user2872856

您需要ORDER BY和LIMIT移动到结束这样的：

SELECT * FROM TABLE_NAME 
WHERE ENGLISH LIKE ? 
UNION ALL 
SELECT * FROM tull 
WHERE BANGLA LIKE ? 
ORDER BY ENGLISH LIMIT 100

不过100行这个总订货会只有英语和限制。每种语言你需要100行吗？如果你想通过这两种语言来命令你可以通过别名别名列和顺序：

SELECT *, ENGLISH AS TEXT FROM tull 
WHERE ENGLISH LIKE ? OR BANGLA LIKE ? 
UNION ALL 
SELECT *, BANGLA AS TEXT FROM tull 
WHERE BANGLA LIKE "" 
ORDER BY TEXT LIMIT 100;

你仍然需要第二个选择参数添加在评论中提到jyanks。

来源

2015-09-27 06:55:18 thoredge

谢谢。这解决了我的问题。 – user2872856

如何实现Android Sqlite Union rawQuery？

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