Erkunden der ParseQuery-Klasse in Android-Entwicklung

parse query kochbuch in android einführung wir haben bereits gesehen, wie ein parsequery parsequery mit get get ein einzelnes parsequery parsequery von back4app abrufen kann es gibt viele andere möglichkeiten, daten mit parsequery parsequery abzurufen, sie können viele objekte auf einmal abrufen, bedingungen für die objekte verwenden, die sie abrufen möchten, und mehr in diesem leitfaden werden sie tief in die parsequery parsequery klasse eintauchen und alle methoden sehen, die sie verwenden können, um ihre abfragen zu erstellen sie werden eine einfache datenbankklasse mit einigen simulierten daten verwenden, um die abfragen über die javascript konsole auf back4app durchzuführen sie können die javascript konsole auf back4app verwenden, um simulierte daten einfach zu erstellen, oder sie können ihre daten mit ihrer eigenen android app erstellen, indem sie diesem leitfaden folgen dieses tutorial verwendet eine app, die in android studio 4 1 1 mit buildtoolsversion=30 0 2 buildtoolsversion=30 0 2 , compile sdk version = 30 0 2 compile sdk version = 30 0 2 und targetsdkversion=30 targetsdkversion=30 jederzeit können sie auf das vollständige android projekt zugreifen, das mit diesem tutorial in unseren github repositories erstellt wurde kotlin beispiel repository java beispiel repository voraussetzungen um dieses tutorial abzuschließen, benötigen wir android studio eine app, die auf back4app erstellt wurde hinweis befolgen sie das tutorial für neue parse apps um zu lernen, wie man eine parse app auf back4app erstellt eine android app, die mit back4app verbunden ist hinweis befolgen sie das tutorial zur installation des parse sdk um ein android studio projekt zu erstellen, das mit back4app verbunden ist ein gerät (oder virtuelles gerät ) mit android 4 1 (jelly bean) oder neuer ziel erforschen sie die parsequery parsequery klasse, verschiedene methoden und lernen sie die abfragetypen kennen, die sie auf android erstellen können die parsequery klasse jede abfrageoperation auf parse verwendet den parsequery parsequery objekttyp, der ihnen hilft, spezifische daten von ihrem back4app in ihrer app abzurufen um eine neue parsequery parsequery , müssen sie als parameter die gewünschte parsequery parsequery unterklasse übergeben, die die abfrageergebnisse enthalten wird es ist entscheidend zu wissen, dass ein parsequery parsequery nur nach dem aufruf einer abrufmethode (wie parsequery find parsequery find oder parsequery get parsequery get ), aufgelöst wird, sodass eine abfrage eingerichtet und mehrere modifikatoren verkettet werden können, bevor sie tatsächlich aufgerufen wird sie können mehr über die parsequery parsequery klasse hier in der offiziellen dokumentation https //parseplatform org/parse sdk android/api/ verwendung der js konsole auf back4app in ihrem back4app anwendungs dashboard finden sie eine sehr nützliche api konsole, in der sie javascript code direkt ausführen können in diesem leitfaden verwenden sie sie, um datenobjekte von back4app zu speichern und abzufragen gehen sie in ihrem haupt dashboard der app zu core >api console >js console core >api console >js console speichern sie ihre datenobjekte um die abfragen in diesem leitfaden auszuführen, müssen sie zunächst ihre app mit einigen daten füllen lassen sie uns eine beispielklasse namens profil profil , die eine soziale medienprofilklasse mit namen berühmter personen und den folgenden feldern nachahmt string typ datums typ zahl (ganzzahl) typ array (string array) typ array (zahlen array) typ geopoint typ nullable zeiger typ hier ist der parse object parse object klassen erstellungscode, also mach weiter und führe ihn in deiner api konsole aus 1 // add profile objects and create table 2 // adam sandler 3 let profile = new parse object('profile'); 4 profile set('name', 'adam sandler'); 5 profile set('birthday', new date('09/09/1966')); 6 profile set('friendcount', 2); 7 profile set('favoritefoods', \['lobster', 'bread']); 8 profile set('luckynumbers', \[2, 7]); 9 profile set('lastloginlocation', new parse geopoint(37 38412167489413, 122 01268034622319)); 10 await profile save(); 11 12 // britney spears 13 profile = new parse object('profile'); 14 profile set('name', 'britney spears'); 15 profile set('birthday', new date('12/02/1981')); 16 profile set('friendcount', 52); 17 profile set('favoritefoods', \['cake', 'bread']); 18 profile set('luckynumbers', \[22, 7]); 19 profile set('lastloginlocation', new parse geopoint(37 38412167489413, 122 01268034622319)); 20 await profile save(); 21 22 // carson kressley 23 profile = new parse object('profile'); 24 profile set('name', 'carson kressley'); 25 profile set('birthday', new date('11/11/1969')); 26 profile set('friendcount', 12); 27 profile set('favoritefoods', \['fish', 'cookies']); 28 profile set('luckynumbers', \[8, 2]); 29 profile set('lastloginlocation', new parse geopoint(37 38412167489413, 122 01268034622319)); 30 await profile save(); 31 32 // dan aykroyd 33 // creates related object membership for this user only 34 let membership = new parse object('membership'); 35 membership set('name', 'premium'); 36 membership set('expirationdate', new date('10/10/2030')) 37 await membership save(); 38 profile = new parse object('profile'); 39 profile set('name', 'dan aykroyd'); 40 profile set('birthday', new date('07/01/1952')); 41 profile set('friendcount', 66); 42 profile set('favoritefoods', \['jam', 'peanut butter']); 43 profile set('luckynumbers', \[22, 77]); 44 profile set('lastloginlocation', new parse geopoint(37 38412167489413, 122 01268034622319)); 45 profile set('premiummembership', membership); 46 await profile save(); 47 48 // eddie murphy 49 profile = new parse object('profile'); 50 profile set('name', 'eddie murphy'); 51 profile set('birthday', new date('04/03/1961')); 52 profile set('friendcount', 49); 53 profile set('favoritefoods', \['lettuce', 'pepper']); 54 profile set('luckynumbers', \[6, 5]); 55 profile set('lastloginlocation', new parse geopoint( 27 104919974838154, 52 61428045237739)); 56 await profile save(); 57 58 // fergie 59 profile = new parse object('profile'); 60 profile set('name', 'fergie'); 61 profile set('birthday', new date('03/27/1975')); 62 profile set('friendcount', 55); 63 profile set('favoritefoods', \['lobster', 'shrimp']); 64 profile set('luckynumbers', \[13, 7]); 65 profile set('lastloginlocation', new parse geopoint( 27 104919974838154, 52 61428045237739)); 66 await profile save(); 67 68 console log('success!'); nachdem sie diesen code ausgeführt haben, sollten sie jetzt eine profil profil klasse in ihrer datenbank mit sechs erstellten objekten haben ihre neue klasse sollte folgendermaßen aussehen lassen sie uns nun beispiele von jeder parsequery parsequery methode ansehen, zusammen mit kurzen erklärungen, was sie tun bitte beachten sie, dass einige methoden in dieser liste optionen optionen als zusätzliches argument annehmen können, aber in den meisten fällen bezieht es sich nur auf masterkey masterkey verwendung und nicht relevant für den inhalt dieses leitfadens ist, sodass diese möglichkeit weggelassen wird, wann immer sie nicht relevant ist abfrage retriever diese methoden sind dafür verantwortlich, die abfrage auszuführen und ihre ergebnisse abzurufen, und sind immer in ihrer abfrageimplementierung vorhanden dies sind die java methoden cancel //cancels the current network request 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query findinbackground(); 3 query cancel(); count //retrieves the count of parseobject results that meet the query criteria 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 try { 3 int querycount = query count(); 4 log d(tag, "count " + querycount); 5 } catch (com parse parseexception parseexception) { 6 parseexception printstacktrace(); 7 } find //this is the basic method for retrieving your query results, always returning an array of parseobject instances, being empty when none are found 1 //this find function works synchronously 2 parsequery\<parseobject> query = new parsequery<>("profile"); 3 try { 4 list\<parseobject> list = query find(); 5 log d(tag, "list " + list); 6 } catch (com parse parseexception e) { 7 e printstacktrace(); 8 } findinbackground //this is the basic method for retrieving your query results, always returning an array of parseobject instances, being empty when none are found 1 //this find function works asynchronously 2 parsequery\<parseobject> query = new parsequery<>("profile"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parseerror ", e); 8 } 9 }); first //retrieves the first parseobject instance that meets the query criteria 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 try { 3 parseobject firstitem = query getfirst(); 4 log d(tag, "first item " + firstitem); 5 } catch (parseexception e) { 6 e printstacktrace(); 7 } get //this quick method is used to retrieve a single parseobject instance when you know its objectid 1 //we can call a parse object with an object id with the get() function 2 parsequery\<parseobject> query = new parsequery<>("profile"); 3 try { 4 parseobject object = query get("c6endlnfdq"); 5 log d(tag, "object " + object); 6 } catch (parseexception e) { 7 e printstacktrace(); 8 } dies sind die kotlin methoden cancel //cancels the current network request 1 val query = parsequery\<parseobject>("profile") 2 query findinbackground() 3 query cancel() count //retrieves the count of parseobject results that meet the query criteria 1 val query = parsequery\<parseobject>("profile") 2 try { 3 val querycount = query count() 4 log d(companion tag, "count $querycount") 5 } catch (parseexception parseexception) { 6 parseexception printstacktrace() 7 } find //this is the basic method for retrieving your query results, always returning an array of parseobject instances, being empty when none are found 1 //this find function works synchronously 2 val query = parsequery\<parseobject>("profile") 3 try { 4 val list = query find() 5 log d(companion tag, "list $list") 6 } catch (e parseexception) { 7 e printstacktrace() 8 } findinbackground //this is the basic method for retrieving your query results, always returning an array of parseobject instances, being empty when none are found 1 //this find function works asynchronously 2 val query = parsequery\<parseobject>("profile") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parseerror ", e) 8 } 9 } first //retrieves the first parseobject instance that meets the query criteria 1 val query = parsequery\<parseobject>("profile") 2 try { 3 val firstitem = query first 4 log d(companion tag, "first item $firstitem") 5 } catch (e parseexception) { 6 e printstacktrace() 7 } get //this quick method is used to retrieve a single parseobject instance when you know its objectid 1 //we can call a parse object with an object id with the get() function 2 val query = parsequery\<parseobject>("profile") 3 try { 4 val `object` = query\["c6endlnfdq"] 5 log d(companion tag, "object $`object`") 6 } catch (e parseexception) { 7 e printstacktrace() 8 } abfragebedingungen diese methoden geben ihnen die möglichkeit, bedingte einschränkungen auf ihre abfrage anzuwenden, die arguably die wichtigsten operationen bei abfragen sind denken sie daran, dass diese operationen alle verkettet werden können, bevor die ergebnisse abgerufen werden, sodass viele kombinationen erreicht werden können, um ihre abfragebedürfnisse zu erfüllen dies sind java methoden containedin //filters objects in which a key value is contained in the provided array of values 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherecontainedin("luckynumbers", list of(2, 7)); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); contains //filters objects in which a string key value contains the provided text value be aware that this condition is case sensitive 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherecontains("name", "da"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); cointansall //filters objects in which an array type key value must contain every value provided 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherecontainsall("luckynumbers", list of(2, 7)); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); containsallstartingwith //filters objects in which an array type key value must contain every string value provided 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherecontainsallstartswith("favoritefoods", list of("shrimp", "lobster")); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); doesnotexist //filters objects in which a key value is not set 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wheredoesnotexist("premiummembership"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); dies sind kotlin methoden containedin //filters objects in which a key value is contained in the provided array of values 1 val query = parsequery\<parseobject>("profile") 2 query wherecontainedin("luckynumbers", java util list of(2, 7)) 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } contains //filters objects in which a string key value contains the provided text value be aware that this condition is case sensitive 1 val query = parsequery\<parseobject>("profile") 2 query wherecontains("name", "da") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } cointansall //filters objects in which an array type key value must contain every value provided 1 val query = parsequery\<parseobject>("profile") 2 query wherecontainsall("luckynumbers", java util list of(2, 7)) 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } containsallstartingwith //filters objects in which an array type key value must contain every string value provided 1 val query = parsequery\<parseobject>("profile") 2 query wherecontainsallstartswith("favoritefoods", java util list of("shrimp", "lobster")) 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } doesnotexist //filters objects in which a key value is not set 1 val query = parsequery\<parseobject>("profile") 2 query wheredoesnotexist("premiummembership") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } dies sind java methoden canceldoesnotmatchkeyinquery //requires that a key’s value does not match a value in an object returned by a different parsequery useful for multi object querying 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 parsequery\<parseobject> innerquery = new parsequery<>("profile"); 3 innerquery wherelessthan("friendcount", 50); 4 query wheredoesnotmatchkeyinquery("friendcount", "friendcount", innerquery); 5 query wheregreaterthan("friendcount", 10); 6 query findinbackground((objects, e) > { 7 if (e == null) { 8 log d(tag, "objects " + objects); 9 } else { 10 log e(tag, "parse error ", e); 11 } 12 }); doesnotmatchquery //requires that an object contained in the given key does not match another query useful for multi object querying 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 parsequery\<parseobject> innerquery = new parsequery<>("membership"); 3 innerquery wheregreaterthan("expirationdate", new date()); 4 query whereexists("premiummembership"); 5 query wheredoesnotmatchquery("premiummembership", innerquery); 6 query findinbackground((objects, e) > { 7 if (e == null) { 8 log d(tag, "objects " + objects); 9 } else { 10 log e(tag, "parse error ", e); 11 } 12 }); endswith //filters objects in which a string key’s value ends with the provided text value 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query whereendswith("name", "ie"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); equalto //filters objects in which a specific key’s value is equal to the provided value 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query whereequalto("friendcount", 2); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); exists //filters objects in which a key value is set 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query whereexists("premiummembership"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); fulltext //filters objects in which a string key’s value wrap matches the provided text value in it it can have many customizable options to improve its results, like language specification and score order 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherefulltext("name", "spears"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); greaterthan //filters objects in which a specific key’s value is greater than the provided value 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 calendar calendar = calendar getinstance(); 3 calendar set(1980, 8, 19, 59, 59, 59); 4 date date = calendar gettime(); 5 query wheregreaterthan("birthday", date); 6 query findinbackground((objects, e) > { 7 if (e == null) { 8 log d(tag, "objects " + objects); 9 } else { 10 log e(tag, "parse error ", e); 11 } 12 }); greaterthanorequalto //filters objects in which a specific key’s value is greater than or equal to the provided value 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wheregreaterthanorequalto("friendcount", 49); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); dies sind kotlin methoden canceldoesnotmatchkeyinquery //requires that a key’s value does not match a value in an object returned by a different parsequery useful for multi object querying 1 val query = parsequery\<parseobject>("profile") 2 val innerquery = parsequery\<parseobject>("profile") 3 innerquery wherelessthan("friendcount", 50) 4 query wheredoesnotmatchkeyinquery("friendcount", "friendcount", innerquery) 5 query wheregreaterthan("friendcount", 10) 6 query findinbackground { objects list\<parseobject>, e parseexception? > 7 if (e == null) { 8 log d(companion tag, "objects $objects") 9 } else { 10 log e(companion tag, "parse error ", e) 11 } 12 } doesnotmatchquery //requires that an object contained in the given key does not match another query useful for multi object querying 1 val query = parsequery\<parseobject>("profile") 2 val innerquery = parsequery\<parseobject>("membership") 3 innerquery wheregreaterthan("expirationdate", date()) 4 query whereexists("premiummembership") 5 query wheredoesnotmatchquery("premiummembership", innerquery) 6 query findinbackground { objects list\<parseobject>, e parseexception? > 7 if (e == null) { 8 log d(companion tag, "objects $objects") 9 } else { 10 log e(companion tag, "parse error ", e) 11 } 12 } endswith //filters objects in which a string key’s value ends with the provided text value 1 val query = parsequery\<parseobject>("profile") 2 query whereendswith("name", "ie") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } equalto //filters objects in which a specific key’s value is equal to the provided value 1 val query = parsequery\<parseobject>("profile") 2 query whereequalto("friendcount", 2) 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } exists //filters objects in which a key value is set 1 val query = parsequery\<parseobject>("profile") 2 query whereexists("premiummembership") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } fulltext //filters objects in which a string key’s value wrap matches the provided text value in it it can have many customizable options to improve its results, like language specification and score order 1 val query = parsequery\<parseobject>("profile") 2 query wherefulltext("name", "spears") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } greaterthan //filters objects in which a specific key’s value is greater than the provided value 1 val query = parsequery\<parseobject>("profile") 2 val calendar = calendar getinstance() 3 calendar\[1980, 8, 19, 59, 59] = 59 4 val date = calendar time 5 query wheregreaterthan("birthday", date) 6 query findinbackground { objects list\<parseobject>, e parseexception? > 7 if (e == null) { 8 log d(companion tag, "objects $objects") 9 } else { 10 log e(companion tag, "parse error ", e) 11 } 12 } greaterthanorequalto //filters objects in which a specific key’s value is greater than or equal to the provided value 1 val query = parsequery\<parseobject>("profile") 2 query wheregreaterthanorequalto("friendcount", 49) 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } dies sind java methoden lessthan //filters objects in which a specific key’s value is lesser than the provided value 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 calendar calendar = calendar getinstance(); 3 calendar set(1980, 8, 19, 59, 59, 59); 4 date date = calendar gettime(); 5 query wherelessthan("birthday", date); 6 query findinbackground((objects, e) > { 7 if (e == null) { 8 log d(tag, "objects " + objects); 9 } else { 10 log e(tag, "parse error ", e); 11 } 12 }); lessthanorequalto //filters objects in which a specific key’s value is lesser than or equal to the provided value 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherelessthanorequalto("friendcount", 49); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); matches //filters objects in which a string type key value must match the provided regular expression and its modifiers 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherematches("name", "da", "i"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); matcheskeyinquery //requires that a key’s value matches a value in an object returned by a different parsequery useful for multi object querying 1 parsequery\<parseobject> query = new parsequery<>("profile"); 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 parsequery\<parseobject> innerquery = new parsequery<>("profile"); 3 innerquery wherelessthan("friendcount", 50); 4 query wherematcheskeyinquery("friendcount", "friendcount", innerquery); 5 query wheregreaterthan("friendcount", 10); 6 query findinbackground((objects, e) > { 7 if (e == null) { 8 log d(tag, "objects " + objects); 9 } else { 10 log e(tag, "parse error ", e); 11 } 12 }); matchesquery //requires that an object contained in the given key matches another query useful for multi object querying 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 parsequery\<parseobject> innerquery = new parsequery<>("membership"); 3 innerquery wheregreaterthan("expirationdate", new date()); 4 query whereexists("premiummembership"); 5 query wherematchesquery("premiummembership", innerquery); 6 query findinbackground((objects, e) > { 7 if (e == null) { 8 log d(tag, "objects " + objects); 9 } else { 10 log e(tag, "parse error ", e); 11 } 12 }); notequalto //filters objects in which a specific key’s value is not equal to the provided value 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherenotequalto("friendcount", 2); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); startswith //filters objects in which a string key’s value starts with the provided text value 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherestartswith("name", "brit"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); dies sind kotlin methoden lessthan //filters objects in which a specific key’s value is lesser than the provided value 1 val query = parsequery\<parseobject>("profile") 2 val calendar = calendar getinstance() 3 calendar\[1980, 8, 19, 59, 59] = 59 4 val date = calendar time 5 query wherelessthan("birthday", date) 6 query findinbackground { objects list\<parseobject>, e parseexception? > 7 if (e == null) { 8 log d(companion tag, "objects $objects") 9 } else { 10 log e(companion tag, "parse error ", e) 11 } 12 } lessthanorequalto //filters objects in which a specific key’s value is lesser than or equal to the provided value 1 val query = parsequery\<parseobject>("profile") 2 query wherelessthanorequalto("friendcount", 49) 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } matches //filters objects in which a string type key value must match the provided regular expression and its modifiers 1 val query = parsequery\<parseobject>("profile") 2 query wherematches("name", "da", "i") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } matcheskeyinquery //requires that a key’s value matches a value in an object returned by a different parsequery useful for multi object querying 1 parsequery\<parseobject> query = new parsequery<>("profile"); 1 val query = parsequery\<parseobject>("profile") 2 val innerquery = parsequery\<parseobject>("profile") 3 innerquery wherelessthan("friendcount", 50) 4 query wherematcheskeyinquery("friendcount", "friendcount", innerquery) 5 query wheregreaterthan("friendcount", 10) 6 query findinbackground { objects list\<parseobject>, e parseexception? > 7 if (e == null) { 8 log d(companion tag, "objects $objects") 9 } else { 10 log e(companion tag, "parse error ", e) 11 } 12 } matchesquery //requires that an object contained in the given key matches another query useful for multi object querying 1 val query = parsequery\<parseobject>("profile") 2 val innerquery = parsequery\<parseobject>("membership") 3 innerquery wheregreaterthan("expirationdate", date()) 4 query whereexists("premiummembership") 5 query wherematchesquery("premiummembership", innerquery) 6 query findinbackground { objects list\<parseobject>, e parseexception? > 7 if (e == null) { 8 log d(companion tag, "objects $objects") 9 } else { 10 log e(companion tag, "parse error ", e) 11 } 12 } notequalto //filters objects in which a specific key’s value is not equal to the provided value 1 val query = parsequery\<parseobject>("profile") 2 query wherenotequalto("friendcount", 2) 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } startswith //filters objects in which a string key’s value starts with the provided text value 1 val query = parsequery\<parseobject>("profile") 2 query wherestartswith("name", "brit") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } abfrageanordnung wesentlich in den meisten abfragen kann die sortierung in parse leicht erreicht und sogar zwischen zwei oder mehr sortierungsbedingungen verkettet werden dies sind java methoden addascending //sort the results in ascending order, overwrites previous orderings multiple keys can be used to solve ordering ties 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query addascendingorder("friendcount"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); adddescending //sort the results in descending order, overwrites previous orderings multiple keys can be used to solve ordering ties 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query adddescendingorder("friendcount"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); ascending //sort the results in ascending order, this can be chained without overwriting previous orderings multiple keys can be used to solve ordering ties 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query orderbyascending("friendcount"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); descending //sort the results in descending order, this can be chained without overwriting previous orderings multiple keys can be used to solve ordering ties 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query orderbydescending("friendcount"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); dies sind kotlin methoden addascending //sort the results in ascending order, overwrites previous orderings multiple keys can be used to solve ordering ties 1 val query = parsequery\<parseobject>("profile") 2 query addascendingorder("friendcount") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } adddescending //sort the results in descending order, overwrites previous orderings multiple keys can be used to solve ordering ties 1 val query = parsequery\<parseobject>("profile") 2 query adddescendingorder("friendcount") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } ascending //sort the results in ascending order, this can be chained without overwriting previous orderings multiple keys can be used to solve ordering ties 1 val query = parsequery\<parseobject>("profile") 2 query orderbyascending("friendcount") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } descending //sort the results in descending order, this can be chained without overwriting previous orderings multiple keys can be used to solve ordering ties 1 val query = parsequery\<parseobject>("profile") 2 query orderbydescending("friendcount") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } feldauswahl diese methoden beeinflussen, welche feldwerte in ihren abfrageergebnissen enthalten sein können dies sind java methoden include //return all fields in the returned objects except the ones specified 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query whereexists("premiummembership"); 3 query include("premiummembership"); 4 query findinbackground((objects, e) > { 5 if (e == null) { 6 log d(tag, "objects " + objects); 7 log d(tag, "object premium membership " + objects get(0) get("premiummembership")); 8 } else { 9 log e(tag, "parse error ", e); 10 } 11 12 }); select //return only the specified fields in the returned objects 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query selectkeys(list of("name")); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 log d(tag, "object name " + objects get(0) get("name")); 7 } else { 8 log e(tag, "parse error ", e); 9 } 10 11 }); dies sind kotlin methoden include //return all fields in the returned objects except the ones specified 1 val query = parsequery\<parseobject>("profile") 2 query whereexists("premiummembership") 3 query include("premiummembership") 4 query findinbackground { objects list\<parseobject>, e parseexception? > 5 if (e == null) { 6 log d(companion tag, "objects $objects") 7 log d( 8 companion tag, 9 "object premium membership " + objects\[0]\["premiummembership"] 10 ) 11 } else { 12 log e(companion tag, "parse error ", e) 13 } 14 } select //return only the specified fields in the returned objects 1 val query = parsequery\<parseobject>("profile") 2 query selectkeys(java util list of("name")) 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 log d(companion tag, "object name " + objects\[0]\["name"]) 7 } else { 8 log e(companion tag, "parse error ", e) 9 } 10 } geopoint abfrage dies sind methoden, die spezifisch für geopoint abfragen sind dies sind java methoden near //order objects by how near the key value is from the given geopoint 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherenear("lastloginlocation", new parsegeopoint(37 38412167489413, 122 01268034622319)); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); polygoncontains //find objects whose key value contains the specified geopoint 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherepolygoncontains("lastloginlocation", new parsegeopoint(37 38412167489413, 122 01268034622319)); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); withingeobox //find objects whose key value is contained within the specified bounding box, composed by two geopoint values that set the lower left and upper right corner values 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherewithingeobox("lastloginlocation", new parsegeopoint(37 48412167489413, 122 11268034622319), new parsegeopoint(37 28412167489413, 121 91268034622319)); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); withinkilometers //find objects whose key value is near the given geopoint and within the maxdistance value the sorted boolean value determines if the results should be sorted by distance ascending 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherewithinkilometers("lastloginlocation", new parsegeopoint(37 38412167489413, 122 01268034622319), 100); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); withinmiles //find objects whose key value is near the given geopoint and within the maxdistance value the sorted boolean value determines if the results should be sorted by distance ascending 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherewithinmiles("lastloginlocation", new parsegeopoint(37 38412167489413, 122 01268034622319), 100); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); withinpolygon //find objects whose key value is contained within the specified polygon, composed of an array of geopoints (at least three) if the polygon path is open, it will be closed automatically by parse connecting the last and first points 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherewithinpolygon("lastloginlocation", list of(new parsegeopoint(37 48412167489413, 122 11268034622319), 3 new parsegeopoint(37 48412167489413, 121 91268034622319), 4 new parsegeopoint(37 28412167489413, 121 91268034622319), 5 new parsegeopoint(37 28412167489413, 122 01268034622319))); 6 query findinbackground((objects, e) > { 7 if (e == null) { 8 log d(tag, "objects " + objects); 9 } else { 10 log e(tag, "parse error ", e); 11 } 12 13 }); withinradians //find objects whose key value is near the given geopoint and within the maxdistance value the sorted boolean value determines if the results should be sorted by distance ascending 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query wherewithinradians("lastloginlocation", new parsegeopoint(37 38412167489413, 122 01268034622319), 100); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); dies sind kotlin methoden near //order objects by how near the key value is from the given geopoint 1 val query = parsequery\<parseobject>("profile") 2 query wherenear("lastloginlocation", parsegeopoint(37 38412167489413, 122 01268034622319)) 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } polygoncontains //find objects whose key value contains the specified geopoint 1 val query = parsequery\<parseobject>("profile") 2 query wherepolygoncontains( 3 "lastloginlocation", 4 parsegeopoint(37 38412167489413, 122 01268034622319) 5 ) 6 query findinbackground { objects list\<parseobject>, e parseexception? > 7 if (e == null) { 8 log d(companion tag, "objects $objects") 9 } else { 10 log e(companion tag, "parse error ", e) 11 } 12 } withingeobox //find objects whose key value is contained within the specified bounding box, composed by two geopoint values that set the lower left and upper right corner values 1 val query = parsequery\<parseobject>("profile") 2 query wherewithingeobox( 3 "lastloginlocation", 4 parsegeopoint(37 48412167489413, 122 11268034622319), 5 parsegeopoint(37 28412167489413, 121 91268034622319) 6 ) 7 query findinbackground { objects list\<parseobject>, e parseexception? > 8 if (e == null) { 9 log d(companion tag, "objects $objects") 10 } else { 11 log e(companion tag, "parse error ", e) 12 } 13 } withinkilometers //find objects whose key value is near the given geopoint and within the maxdistance value the sorted boolean value determines if the results should be sorted by distance ascending 1 val query = parsequery\<parseobject>("profile") 2 query wherewithinkilometers( 3 "lastloginlocation", 4 parsegeopoint(37 38412167489413, 122 01268034622319), 5 100 0 6 ) 7 query findinbackground { objects list\<parseobject>, e parseexception? > 8 if (e == null) { 9 log d(companion tag, "objects $objects") 10 } else { 11 log e(companion tag, "parse error ", e) 12 } 13 } withinmiles //find objects whose key value is near the given geopoint and within the maxdistance value the sorted boolean value determines if the results should be sorted by distance ascending 1 val query = parsequery\<parseobject>("profile") 2 query wherewithinmiles( 3 "lastloginlocation", 4 parsegeopoint(37 38412167489413, 122 01268034622319), 5 100 0 6 ) 7 query findinbackground { objects list\<parseobject>, e parseexception? > 8 if (e == null) { 9 log d(companion tag, "objects $objects") 10 } else { 11 log e(companion tag, "parse error ", e) 12 } 13 } withinpolygon //find objects whose key value is contained within the specified polygon, composed of an array of geopoints (at least three) if the polygon path is open, it will be closed automatically by parse connecting the last and first points 1 val query = parsequery\<parseobject>("profile") 2 query wherewithinpolygon( 3 "lastloginlocation", java util list of( 4 parsegeopoint(37 48412167489413, 122 11268034622319), 5 parsegeopoint(37 48412167489413, 121 91268034622319), 6 parsegeopoint(37 28412167489413, 121 91268034622319), 7 parsegeopoint(37 28412167489413, 122 01268034622319) 8 ) 9 ) 10 query findinbackground { objects list\<parseobject>, e parseexception? > 11 if (e == null) { 12 log d(companion tag, "objects $objects") 13 } else { 14 log e(companion tag, "parse error ", e) 15 } 16 } withinradians //find objects whose key value is near the given geopoint and within the maxdistance value the sorted boolean value determines if the results should be sorted by distance ascending 1 val query = parsequery\<parseobject>("profile") 2 query wherewithinradians( 3 "lastloginlocation", 4 parsegeopoint(37 38412167489413, 122 01268034622319), 5 100 0 6 ) 7 query findinbackground { objects list\<parseobject>, e parseexception? > 8 if (e == null) { 9 log d(companion tag, "objects $objects") 10 } else { 11 log e(companion tag, "parse error ", e) 12 } 13 } pagination diese methoden beziehen sich auf pagination utilities, die nützlich sind für abfragen, die eine große anzahl von ergebnissen abrufen dies sind java methoden limit //sets the maximum value of returned results, the default value is 100 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query setlimit(2); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); skip //skips the first n results in the query, essential for pagination 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query setskip(2); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); dies sind kotlin methoden limit //sets the maximum value of returned results, the default value is 100 1 val query = parsequery\<parseobject>("profile") 2 query limit = 2 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } skip //skips the first n results in the query, essential for pagination 1 val query = parsequery\<parseobject>("profile") 2 query skip = 2 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } lokaler datenspeicher diese methoden ermöglichen die auswahl der quelle der abfragen und die verwendung eines lokalen datenspeichers dies sind java methoden fromlocaldatastore //changes the source of this query to all pinned objects 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 //if you want use localdatastore you should enable local data store in the app java or app kt file 3 query fromlocaldatastore(); 4 query findinbackground((objects, e) > { 5 if (e == null) { 6 log d(tag, "objects " + objects); 7 } else { 8 log e(tag, "parse error ", e); 9 } 10 11 }); fromnetwork //changes the source of this query to your online server 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query fromnetwork(); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); frompin //changes the source of this query to the default group of pinned objects 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query frompin(); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 10 }); frompinwithname //changes the source of this query to a specific group of pinned objects 1 parsequery\<parseobject> query = new parsequery<>("profile"); 2 query frompin("pinnedobjects"); 3 query findinbackground((objects, e) > { 4 if (e == null) { 5 log d(tag, "objects " + objects); 6 } else { 7 log e(tag, "parse error ", e); 8 } 9 }); das sind kotlin methoden fromlocaldatastore //changes the source of this query to all pinned objects 1 val query = parsequery\<parseobject>("profile") 2 //if you want use localdatastore you should enable local data store in the app java or app kt file 3 query fromlocaldatastore() 4 query findinbackground { objects list\<parseobject>, e parseexception? > 5 if (e == null) { 6 log d(companion tag, "objects $objects") 7 } else { 8 log e(companion tag, "parse error ", e) 9 } 10 } fromnetwork //changes the source of this query to your online server 1 val query = parsequery\<parseobject>("profile") 2 query fromnetwork() 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } frompin //changes the source of this query to the default group of pinned objects 1 val query = parsequery\<parseobject>("profile") 2 query frompin() 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } frompinwithname //changes the source of this query to a specific group of pinned objects 1 val query = parsequery\<parseobject>("profile") 2 query frompin("pinnedobjects") 3 query findinbackground { objects list\<parseobject>, e parseexception? > 4 if (e == null) { 5 log d(companion tag, "objects $objects") 6 } else { 7 log e(companion tag, "parse error ", e) 8 } 9 } fazit am ende dieses leitfadens haben sie gelernt, wie man verschiedene abfragetypen in android verwendet