sqlite in Android Method Example for Removing Duplicate Values When Querying Data
- 2021-11-01 04:50:35
- OfStack
1. Mode 1:
/**
* Parameter 1 : Do you want to remove weight
* Parameter 2 : Table name
* Parameter 3 : columns Represents the fields of the query ,new String[]{MODEL} Indicates querying the schema in the table (also indicates the result of the query)
* Parameter thinking: selection Represents the conditions of the query, PHONE_NUMBER+" = ?" Indicates the query mode according to the mobile phone number
* Parameter 5 : selectionArgs Represents the value corresponding to the query condition ,new String[]{phoneNumber} Represents the value corresponding to the query condition
* Parameter 6 : String groupBy Grouping
* Parameter 7 : String having
* Parameter 8 : orderBy Indicates according to what sort ,
* Parameter 9 : limit Limit the number of rows returned by the query, NULL Represents an unrestricted clause
**/
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);
The full query code is as follows:
/**
* Query scenic spot data according to scenic spot name
* @param areaName
* @return 0 Interception mode was not found (that is, interception mode was not set for this mobile phone number) 1 : Intercept text messages 2 Intercept a call 3 : Intercept all
**/
public List<ScenicSpot> getScenicAreas(String areaName){
ArrayList<ScenicSpot> scenicSpotList = new ArrayList<>();
String model = "0";
SQLiteDatabase readableDatabase = mSmartTourSQLiteOpenHelper.getReadableDatabase();
/**
* Parameter 1 : Do you want to remove weight
* Parameter 2 : Table name
* Parameter 3 : columns Represents the fields of the query ,new String[]{MODEL} Indicates querying the schema in the table (also indicates the result of the query)
* Parameter thinking: selection Represents the conditions of the query, PHONE_NUMBER+" = ?" Indicates the query mode according to the mobile phone number
* Parameter 5 : selectionArgs Represents the value corresponding to the query condition ,new String[]{phoneNumber} Represents the value corresponding to the query condition
* Parameter 6 : String groupBy Grouping
* Parameter 7 : String having
* Parameter 8 : orderBy Indicates according to what sort ,
* Parameter 9 : limit Limit the number of rows returned by the query, NULL Represents an unrestricted clause
**/
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;
}
Mode 2:
String sql = "select distinct "
+ TYPENAME
+ " from "
+ TABLE_NAME
+ " ORDER BY " + TYPE + " ASC";
Cursor c = db.rawQuery(sql, null);
Complete code:
/**
* @return All organizational structure names
**/
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;
}
}
Summarize