database - How to query android sqlite for specific category in table? -

i have database created sqlite in android , want able list contacts in specific group. database helper code this;

public class databasehelper extends sqliteopenhelper {  public static final string database_name = "contact.db"; public static final int database_version = 1; context context;  public databasehelper(context context) {     super(context, database_name, null, database_version);     this.context = context; }  @override public void oncreate(sqlitedatabase db) {     db.execsql(table.contact.create_contact_details_tables);     db.execsql(table.country.create_country_tables);     db.execsql(table.state.create_state_tables);     db.execsql(table.city.create_city_tables);     db.execsql(table.category.create_category_tables);     createdefaults(db);     createcatgeorytype(db); }  private void createdefaults(sqlitedatabase db) {     string[] country = context.getresources().getstringarray(r.array.country_arrays);     (string acountry : country) {         contentvalues contentvalues = new contentvalues();         contentvalues.put(table.country.country_name, acountry);         db.insert(table.country.table_name, null, contentvalues);     }  }  private void createcatgeorytype(sqlitedatabase db) {     string[] category = context.getresources().getstringarray(r.array.category_arrays);     (string acategory : category) {         contentvalues contentvalues = new contentvalues();         contentvalues.put(table.category.category_type, acategory);         db.insert(table.category.table_name, null, contentvalues);     }  }  @override public void onupgrade(sqlitedatabase db, int oldversion, int newversion) {  }  public long insert(context context, string tablename, contentvalues contentvalues) {      databasehelper databasehelper = null;     sqlitedatabase sqlitedatabase = null;      long row_id = -1;     try {         databasehelper = new databasehelper(context);         sqlitedatabase = databasehelper.getwritabledatabase();         if (sqlitedatabase != null) {             row_id = sqlitedatabase.insertwithonconflict(tablename, null, contentvalues, sqlitedatabase.conflict_abort);         }      } catch (exception e) {         e.printstacktrace();         if (databasehelper != null)             databasehelper.close();         if (sqlitedatabase != null)             sqlitedatabase.close();     } {         if (databasehelper != null)             databasehelper.close();         if (sqlitedatabase != null) {             sqlitedatabase.close();         }     }     return row_id; }  public long update(context context, string tablename, contentvalues contentvalues, string _id) {     databasehelper databasehelper = null;     sqlitedatabase sqlitedatabase = null;     long row_id = 0;      try {         databasehelper = new databasehelper(context);         sqlitedatabase = databasehelper.getwritabledatabase();          row_id = sqlitedatabase.update(tablename, contentvalues, " _id =" + _id, null);     } catch (exception e) {         e.printstacktrace();         assert databasehelper != null;         databasehelper.close();         assert sqlitedatabase != null;         sqlitedatabase.close();     } {         assert databasehelper != null;         databasehelper.close();         assert sqlitedatabase != null;         sqlitedatabase.close();     }     if (row_id > 0) {         log.d("no of updated row is", "1");     }     return row_id; } 

}

and table class this;

public class table { public static class contact {     public static final string table_name = "contact_details";     public static final string             _id = "_id",             name = "name",             email = "email",             photo_url = "photo_url",             mobile = "mobile",             landline = "landline",             address = "address",             state = "state",             country = "country",             city = "city",             company_name = "company_name",             website = "website",             category_type = "category_type";      public static final string create_contact_details_tables = " create table " +             table_name             + "(" + _id + " integer primary key autoincrement, "             + name + " text, "             + email + " text, "             + photo_url + " text, "             + mobile + " text, "             + landline + " text, "             + address + " text, "             + state + " text, "             + country + " text, "             + city + " text, "             + company_name + " text, "             + category_type + " text, "             + website + " text " + ")";  }  public static class country {     public static final string table_name = "country";     public static final string             country_id = "country_id",             country_name = "country_name";       public static final string create_country_tables = " create table " +             table_name             + "(" + country_id + " integer primary key autoincrement, "             + country_name + " text " + ")";  }   public static class state {     public static final string table_name = "state";     public static final string             state_id = "state_id",             country_id = "country_id",             state_name = "state_name";      public static final string create_state_tables = " create table " +             table_name             + "(" + state_id + " integer primary key autoincrement, "             + country_id + " text, "             + state_name + " text " + ")";  }  public static class city {     public static final string table_name = "city";     public static final string             country_id = "country_id",             state_id = "state_id",             city_id = "city_id",             city_name = "city_name";      public static final string create_city_tables = " create table " +             table_name             + "(" + city_id + " integer primary key autoincrement, "             + country_id + " text, "             + state_id + " text, "             + city_name + " text " + ")";  }  public static class category {     public static final string table_name = "category_type";     public static final string             cat_id = "cat_id",             category_type = "category_type";       public static final string create_category_tables = " create table " +             table_name             + "(" + cat_id + " integer primary key autoincrement, "             + category_type + " text " + ")"; } 

}

the array of category type added table category in sqlite are;

• friends
• family
• office
• other

i need on how select contacts created under specific category. far query select contacts , populate listview adapter without categorizing;

public void getdetaillist() {     maparraylist = new arraylist<>();     databasehelper dbhelper = null;     sqlitedatabase sqlitedatabase;       try {         dbhelper = new databasehelper(getactivity());         sqlitedatabase = dbhelper.getreadabledatabase();         hashmap<string, object> hashmap;         cursor = sqlitedatabase.rawquery("select * " +                 table.contact.table_name + " ct , "                 + table.country.table_name + " co ,"                 + table.category.table_name + " ca where" +                 " ct." + table.contact.country +                 " = co." + table.country.country_id                 + " , " +                 " ct." + table.contact.category_type +                 " = ca." + table.category.cat_id + " order " + table.contact.name + " asc ", null);           while (cursor.movetonext()) {             hashmap = new hashmap<>();             hashmap.put("_id", cursor.getstring(cursor.getcolumnindex(table.contact._id)));             hashmap.put(fields[1], cursor.getstring(cursor.getcolumnindex(table.contact.name)));             hashmap.put(fields[2], cursor.getstring(cursor.getcolumnindex(table.contact.mobile)));             hashmap.put(fields[3], cursor.getstring(cursor.getcolumnindex(table.contact.landline)));             hashmap.put(fields[4], cursor.getstring(cursor.getcolumnindex(table.contact.email)));             hashmap.put(fields[5], cursor.getstring(cursor.getcolumnindex(table.contact.address)));             hashmap.put(fields[6], cursor.getstring(cursor.getcolumnindex(table.country.country_name)));             hashmap.put(fields[7], cursor.getstring(cursor.getcolumnindex(table.contact.state)));             hashmap.put(fields[8], cursor.getstring(cursor.getcolumnindex(table.contact.city)));             hashmap.put(fields[9], cursor.getstring(cursor.getcolumnindex(table.contact.company_name)));             hashmap.put(fields[10], cursor.getstring(cursor.getcolumnindex(table.contact.website)));             hashmap.put(fields[11], cursor.getstring(cursor.getcolumnindex(table.category.category_type)));             hashmap.put("image", cursor.getstring(cursor.getcolumnindex(table.contact.photo_url)));             maparraylist.add(hashmap);         }         cursor.close();     } catch (exception e) {         e.printstacktrace();     } {         assert dbhelper != null;         dbhelper.close();     }      adapter = new contactlistadapter(getactivity(), r.layout.contact_list,             r.id.imgcontact, r.id.tvcontact, r.id.tvnumber, r.id.tvemail, maparraylist);     listview.setadapter(adapter);   } 

please me modify query in above snippet atleast listview populate contacts specific group.

thank in advance.

try below query contact name have specific category & country

select name contact_details category_type = 'friends' , country = 'xyz'