如何为我的SQLITE数据库按降序排序,Android应用程序?
发布时间:2020-12-12 19:18:16 所属栏目:百科 来源:网络整理
导读:什么是以降序显示我的数据的最有效的方法? public String getRank() { String[] rank = new String[]{ KEY_ROWID }; Cursor c = scoreDb.query(DATABASE_TABLE,rank,null,null); //reading information from db. String rankResult = ""; int iRow = c.getC
什么是以降序显示我的数据的最有效的方法?
public String getRank() { String[] rank = new String[]{ KEY_ROWID }; Cursor c = scoreDb.query(DATABASE_TABLE,rank,null,null); //reading information from db. String rankResult = ""; int iRow = c.getColumnIndex(KEY_ROWID); //Cursor looking for column setting equal to these ints. for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) { //Move to first row - where cursor starts and moves to next row as long it is not after last row. rankResult = rankResult + c.getString(iRow) + "n"; //Returning value of row that it is currently on. } return rankResult; //returning result } public String getName() { String[] name = new String[]{ KEY_NAME }; Cursor c = scoreDb.query(DATABASE_TABLE,name,null); //reading information from db. String nameResult = ""; int iRow1 = c.getColumnIndex(KEY_NAME); //Cursor looking for column setting equal to these ints. for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) { //Move to first row - where cursor starts and moves to next row as long it is not after last row. nameResult = nameResult + c.getString(iRow1) + "n"; //Returning value of row that it is currently on. } return nameResult; //returning result } public String getScore() { String[] score = new String[]{ KEY_SCORE }; Cursor c = scoreDb.query(DATABASE_TABLE,score,null); //reading information from db. String scoreResult = ""; int iRow2 = c.getColumnIndex(KEY_SCORE); //Cursor looking for column setting equal to these ints. for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) { //Move to first row - where cursor starts and moves to next row as long it is not after last row. scoreResult = scoreResult + c.getString(iRow2) + "n"; //Returning value of row that it is currently on. } return scoreResult; //returning result }查询有两种语法,你使用的语法,最后一列代表顺序,你只需要指定你要做什么列order by“ASC”(或)orderby“DESC” Cursor c = scoreDb.query(DATABASE_TABLE,yourColumn+" DESC"); 参考this文档了解更多关于查询方法。 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |