Android中的sqlite查询数据时去掉重复值的方法实例

    /**
     * 参数一：是否去重
     * 参数二：表名
     * 参数三：columns 表示查询的字段,new String[]{MODEL}表示查询该表当中的模式（也表示查询的结果）
     * 参数思：selection表示查询的条件，PHONE_NUMBER+" = ?" 表示根据手机号去查询模式
     * 参数五：selectionArgs 表示查询条件对应的值,new String[]{phoneNumber}表示查询条件对应的值
     * 参数六：String groupBy 分组
     * 参数七：String having
     * 参数八：orderBy 表示根据什么排序,
     * 参数九：limit 限制查询返回的行数，NULL表示无限制子句
     **/
    Cursor cursor = readableDatabase.query(true,TABLE_NAME, new String[]{DESCRIPTION,ID,IMAGE_URL,LATITUDE,LONGITUDE,NAME,NEED_AUDIO,SPOT_TYPE,TGROUP,AUDIO_NAME,AREA_NAME}, AREA_NAME + " = ?", new String[]{areaName}, null, null, null,null);

/**
* 根据景区名称查询景点数据
* @param areaName
* @return 0：未查询到拦截模式（也就是该手机号没有设置拦截模式） 1：拦截短信 2：拦截电话 3：拦截所有
**/
public List<ScenicSpot  getScenicAreas(String areaName){
ArrayList<ScenicSpot  scenicSpotList = new ArrayList< ();
String model = "0";
SQLiteDatabase readableDatabase = mSmartTourSQLiteOpenHelper.getReadableDatabase();
/**
* 参数一：是否去重
* 参数二：表名
* 参数三：columns 表示查询的字段,new String[]{MODEL}表示查询该表当中的模式（也表示查询的结果）
* 参数思：selection表示查询的条件，PHONE_NUMBER+" = ?" 表示根据手机号去查询模式
* 参数五：selectionArgs 表示查询条件对应的值,new String[]{phoneNumber}表示查询条件对应的值
* 参数六：String groupBy 分组
* 参数七：String having
* 参数八：orderBy 表示根据什么排序,
* 参数九：limit 限制查询返回的行数，NULL表示无限制子句
**/
Cursor cursor = readableDatabase.query(true,TABLE_NAME, new String[]{DESCRIPTION,ID,IMAGE_URL,LATITUDE,LONGITUDE,NAME,NEED_AUDIO,SPOT_TYPE,TGROUP,AUDIO_NAME,AREA_NAME}, AREA_NAME + " = ?", new String[]{areaName}, null, null, null,null);
while (cursor.moveToNext()){
ScenicSpot scenicSpot = new ScenicSpot();
String description = cursor.getString(cursor.getColumnIndex(DESCRIPTION));
String id = cursor.getString(cursor.getColumnIndex(ID));
String image_url = cursor.getString(cursor.getColumnIndex(IMAGE_URL));
String latitude = cursor.getString(cursor.getColumnIndex(LATITUDE));
String longitude = cursor.getString(cursor.getColumnIndex(LONGITUDE));
String name = cursor.getString(cursor.getColumnIndex(NAME));
String need_audio = cursor.getString(cursor.getColumnIndex(NEED_AUDIO));
String spot_type = cursor.getString(cursor.getColumnIndex(SPOT_TYPE));
String tgroup = cursor.getString(cursor.getColumnIndex(TGROUP));
String audio_name = cursor.getString(cursor.getColumnIndex(AUDIO_NAME));
String area_name = cursor.getString(cursor.getColumnIndex(AREA_NAME));
scenicSpot.setDescription(description);
scenicSpot.setId(id);
scenicSpot.setImageurl(image_url);
scenicSpot.setLatitude(latitude);
scenicSpot.setLongitude(longitude);
scenicSpot.setName(name);
scenicSpot.setNeedAudio(need_audio);
scenicSpot.setSpotType(spot_type);
scenicSpot.setTgroup(tgroup);
scenicSpot.setAudioname(audio_name);
scenicSpot.setAreaName(area_name);
scenicSpotList.add(scenicSpot);
}
cursor.close();
readableDatabase.close();
return scenicSpotList;
}

String sql = "select distinct "
+ TYPENAME
+ " from "
+ TABLE_NAME 
+ " ORDER BY " + TYPE + " ASC";
Cursor c = db.rawQuery(sql, null);

/**
* @return 所有组织结构名称
**/
public static List<String  queryTypeNames() {
synchronized (DatabaseHelper.lock) {
List<String  types = null;
SQLiteDatabase db = DatabaseHelper.getInstance().getReadableDatabase();
try {
String sql = "select distinct "
+ TYPENAME
+ " from "
+ TABLE_NAME 
+ " ORDER BY " + TYPE + " ASC";
Cursor c = db.rawQuery(sql, null);
while (c.moveToNext()) {
String type = c.getString(c.getColumnIndex(TYPENAME));
if (types == null) {
types = new ArrayList<String ();
}
if (type != null && type.length()   1) {
types.add(type);
}
}
db.close();
return types;
} catch (Exception e) {
db.close();
}
return types;
}
}