Question

我正在尝试使用像％userCriteria％这样的LIKE语句来查询我的数据库。我有一个包含以下列的表（存储在MySQLiteHelper中）：

        MySQLiteHelper.COLUMN_DESCRIPTION,
        MySQLiteHelper.COLUMN_PUB_DATE,
        MySQLiteHelper.COLUMN_TITLE,
        MySQLiteHelper.COLUMN_USER_SPEC_NAME,
        MySQLiteHelper.COLUMN_LINK

我想创建一个查询，它只返回TITLE列中包含特定字符串的条目。

我正在实现的方法（应该执行查询）在我的dataSourseClass中看起来像这样：

 public ArrayList<RssItem> read(String selection, String[] selectionArgs, String groupBy, String having, String orderBy) {
    ArrayList<RssItem> tasks = new ArrayList<RssItem>();

    Cursor cursor = mDatabase.query(MySQLiteHelper.TABLE_NAME, new String[]{allColumns[3]}, selection, selectionArgs, groupBy, having, orderBy);

    cursor.moveToFirst();
    while (!cursor.isAfterLast()) {
        RssItem task = cursorToTask(cursor);
        tasks.add(task);
        cursor.moveToNext();
    }
    // Make sure to close the cursor
    cursor.close();
    return tasks;

}

allColumns：

private String[] allColumns = {
        MySQLiteHelper.COLUMN_ID,
        MySQLiteHelper.COLUMN_DESCRIPTION,
        MySQLiteHelper.COLUMN_PUB_DATE,
        MySQLiteHelper.COLUMN_TITLE,
        MySQLiteHelper.COLUMN_USER_SPEC_NAME,
        MySQLiteHelper.COLUMN_LINK
};

这就是我在Activity中调用read方法的方法：

private void searchDatabase(String searchCriteriaTitle) {
    //clear the data from the adapter...
    mAdapter.clear();
    //get all of the stored records (during the parsing process)...
    List<RssItem> items = rssItemDataSource.read(MySQLiteHelper.COLUMN_TITLE + " LIKE ?",new String[]{searchCriteriaTitle},null,null,null);

    //if the search criteria is not empty string...
    if(!searchedItem.equals("")){
        for(int i = 0; i < items.size();i++) {
            //search from a match against the user's search criteria...

            mAdapter.add(items.get(i));

        }
    }
    //if the search criteria is am empty string...
    else{
        //read all of the
        List<RssItem> allItems = rssItemDataSource.getAllTasks();
       //add all...
        for(int i = 0; i < allItems.size();i++) {
            mAdapter.add(allItems.get(i));
        }
    }
}

现在返回的条目列表是空的，我不明白为什么。有什么建议？

Answer 1

你试过吗？

 List<RssItem> items = rssItemDataSource.read(MySQLiteHelper.COLUMN_TITLE + " LIKE ?", new String[]{"%"+searchCriteriaTitle+"%"},null,null,null);

Answer 2

你能试试吗

    Cursor cursor = mDatabase rawQuery("select "+COLUMN_TITLE +"from "+MySQLiteHelper.TABLE_NAME+" where "+MySQLiteHelper.COLUMN_TITLE+" LIKE \'?\'", new String[]{"userCriteria"});
    if(cursor.moveToFirst()){
      do {
          RssItem task = cursorToTask(cursor);
          tasks.add(task);
          cursor.moveToNext();
    }while (cursor.moveToNext());
}

SQLite LIKE选择不起作用

2 个答案: