Android:sqliteopenhelper and Greendao Database operations

Original address: Http://blog.csdn.net/intbird

The project is using Greedao,sqllite, which was previously practiced,

If the project all use this, people will be more tired;

However, Greendao is easy to use and can be said to be a three-minute crash.

If you do not understand, please see the official documents, the source code is also described in detail.

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@GreenDao

Website Link:http://greendao-orm.com/documentation/how-to-get-started/

Website Demo: Https://github.com/greenrobot/greenDAO

public static void Save (Locations locs) {sqlitedatabase db = Frame.getinstance (). Getdbhelp (). Getwritabledatabase ();D Aomaster master = new Daomaster (db);D aosession session = master.newsession ();D Blocationsdao Locsdao = Session.getdblocationsdao (); Locsdao.insertorreplace (locs);;d b.close ();} public static void Deletedfromlast (Long LastID) {Sqlitedatabase db = Frame.getinstance (). Getdbhelp (). Getwritabledatabase ();D aomaster master = new Daomaster (db);D aosession session = master.newsession ();D Blocationsdao Locsdao = Session.getdblocationsdao (); querybuilder<dblocations> query = Locsdao.querybuilder ();D eletequery<dblocations> delete = Query.where ( Properties.Time.le (LastID)). Builddelete ();d elete.executedeletewithoutdetachingentities ();d b.close (); public static long Getdbsize () {Sqlitedatabase db = Frame.getinstance (). Getdbhelp (). Getwritabledatabase ();D Aomaster master = new Daomaster (db);D aosession session = master.newsession ();D Blocationsdao Locsdao = Session.getdblocationsdao ( ); longSize = Locsdao.querybuilder (). Count (); return size;} public static list<dblocations> getdatabysize (int size) {Sqlitedatabase db = Frame.getinstance (). Getdbhelp (). Getwritabledatabase ();D aomaster master = new Daomaster (db);D aosession session = master.newsession ();D Blocationsdao Locsdao = Session.getdblocationsdao (); list<dblocations> list = Locsdao.querybuilder (). limit (size). ORDERASC (Properties.time). Build (). List (); Db.close (); return list;}

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@SqlLiteOpenHelper

Example

Package Mode;import Java.util.arraylist;import Java.util.hashmap;import java.util.map;import Core.override.myselfdishadapter;import Android.content.contentvalues;import Android.content.context;import Android.database.cursor;import android.database.sqlite.*;p ublic class Dishsqlite extends Sqliteopenhelper {private Static final String tb_name = "Tb_dishmode";p rivate static final String create_table_sql = "CREATE TABLE" +tb_name+ "(" + Di shmode.ds_id+ "Integer primary key AutoIncrement," + dishmode.ds_name+ "text," + dishmode.ds_cover+ "text," + Dishmode.ds_ img+ "text," + dishmode.ds_tips+ "text," + dishmode.ds_addtime+ "text)";p ublic dishsqlite (context context) {Super (conte XT, Tb_name, NULL, 1);} @Overridepublic void OnCreate (Sqlitedatabase db) {db.execsql (create_table_sql);} @Overridepublic void Onupgrade (sqlitedatabase db, int oldversion, int newversion) {//Db.execsql ("ALTER TABLE tb_student A DD COLUMN Other string ");//Schma_version}public void ExecuteSQL (STRING sql) {This.getwritabledaTabase (). execsql (SQL); This.getwritabledatabase (). Close (); /**** Query **/public arraylist<map<string,string>> getalldataindb (String State) {arraylist<map< string,string>> Listmap = new arraylist<map<string,string>> ();  Cursor cur = getwritabledatabase (). query (tb_name, NULL, NULL, null,null, NULL, NULL);//query and get cursor if (Cur.movetofirst ()) {// Determines whether the cursor is empty do {map<string,string> map=new hashmap<string, string> (), int id = cur.getint (cur.getcolumnindex ( dishmode.ds_id)); String statedb=cur.getstring (Cur.getcolumnindex (dishmode.ds_state)); if (Statedb.equals (state)) {string name= Cur.getstring (Cur.getcolumnindex (dishmode.ds_name)); String dishcover=cur.getstring (Cur.getcolumnindex (dishmode.ds_cover)); String dishtime=cur.getstring (Cur.getcolumnindex (Dishmode.ds_addtime)), Map.put ("id", id+ ""), Map.put ("style", myselfdishadapter.stylenormal+ ""); Map.put ("name", name), Map.put ("img", Dishcover); Map.put ("Addtime", dishtime); Listmap.add (map);}} while (Cur.movetonext ()); cur. Close (); This.getwritabledatabase (). Close (); return listmap;} /** * Inserting a piece of data; */public int Insert (Dishmode updata) {contentvalues CV = new Contentvalues (); Cv.put (Dishmode.ds_name, Updata.getname ()) ; Cv.put (Dishmode.ds_cover, Updata.getcover ()); Cv.put (Dishmode.ds_img, updata.getimg ()); Cv.put (DishMode.ds_state, Updata.getstate ()); Cv.put (Dishmode.ds_burden, Updata.getburden ()); Cv.put (Dishmode.ds_makes, UpData.getMakes ()); Cv.put (Dishmode.ds_tips, Updata.gettips ()); Cv.put (Dishmode.ds_addtime, Updata.getaddtime ()); Long id = This.getwritabledatabase (). Insert (Tb_name, NULL, CV), This.getwritabledatabase (). Close (); return (int) ID;} /** * Modify a piece of data; */public int update (Dishmode updata) {contentvalues CV = new Contentvalues (); Cv.put (Dishmode.ds_name, Updata.getname ()) ; Cv.put (Dishmode.ds_cover, Updata.getcover ()); Cv.put (Dishmode.ds_img, updata.getimg ()); Cv.put (DishMode.ds_state, Updata.getstate ()); Cv.put (Dishmode.ds_burden, Updata.getburden ()); Cv.put (Dishmode.ds_makes, UpData.getMakes ()); Cv.put (Dishmode.ds_Tips, Updata.gettips ()), Cv.put (Dishmode.ds_addtime, Updata.getaddtime ()), int row= this.getwritabledatabase (). Update (Tb_name, cv,null,null); This.getwritabledatabase (). Close (); return row;} /** * Delete */public boolean deletebyid (int id) {int i = this.getwritabledatabase (). Delete (Tb_name, dishmode.ds_id+ "=" + int Eger.valueof (ID) + "", null); This.getwritabledatabase (). Close (); if (i > 0) return True;elsereturn false;}

Android:sqliteopenhelper and Greendao Database operations