Common errors with Android SQLite

The use of leisure to write a simple SQL statement operation SQLite database, in the use of Simplecursoradapter an exception for a long time have not solved

Process:com.example.chunchuner.usesqltest405, pid:31206
Java.lang.IllegalArgumentException:column ' _id ' does not exist

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Use Simplecursoradapter to encapsulate the cursor when the cursor requires that the column name of the underlying database's primary key column be _id
Otherwise, a java.lang.IllegalArgumentException exception will occur.

The code is as follows:

Package Com.example.nanchen.usesqltest405;import Android.database.cursor;import Android.database.sqlite.sqlitedatabase;import Android.database.sqlite.sqliteexception;import Android.os.Bundle; Import Android.support.v7.app.appcompatactivity;import Android.view.view;import Android.widget.button;import Android.widget.cursoradapter;import Android.widget.edittext;import Android.widget.listview;import    Android.widget.simplecursoradapter;public class Mainactivity extends appcompatactivity {private Button insert;    Private EditText textview_title,textview_content;    Private Sqlitedatabase DB;    Private ListView ListView;        @Override protected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);        Setcontentview (R.layout.activity_main);        Create or open a database (you need to use absolute path here) db = Sqlitedatabase.openorcreatedatabase (This.getfilesdir (). toString () + "/MY.DB3", null);        Insert = (Button) Findviewbyid (R.id.insert); ListView = (ListView) FindviewByid (R.id.listview);        Textview_title = (EditText) Findviewbyid (R.id.title_text);        Textview_content = (EditText) Findviewbyid (r.id.content);                Insert.setonclicklistener (New View.onclicklistener () {@Override public void OnClick (View v) {                String title = Textview_title.gettext (). toString ();                String content = Textview_content.gettext (). toString ();                try {insertdata (db, title, content);  }catch (sqliteexception e) {//Execute CREATE DATABASE table Db.execsql ("CREATE Table News_inf (_id integer                    Primary key AutoIncrement, "+" News_title varchar2,news_content varchar2) ";                InsertData (DB, title, content);                } cursor cursor = db.rawquery ("SELECT * from News_inf", null);            Inflatelist (cursor);    }        }); } private void InsertData (Sqlitedatabase db,string Title,string content) {db.execsql ("INSERT into news_inf values (null,?,?)", New String[]{title, content}); } private void Inflatelist (cursor cursor) {//Fill Simplecursoradapter//Use Simplecursoradapter to encapsulate cursor when curso R requires the column name of the primary key column for the underlying database to be _id//or Java.lang.IllegalArgumentException exception will occur simplecursoradapter adapter = new SIMPLECU Rsoradapter (this, Android. R.layout.simple_list_item_1,cursor, new string[]{"News_title", "News_content"}, New Int[]{r.i        D.title_text,r.id.content}, Cursoradapter.flag_register_content_observer);    Display Data Listview.setadapter (adapter);        } @Override protected void OnDestroy () {Super.ondestroy ();        When exiting the program, close Sqlitedatabase if (db! = null && db.isopen ()) {db.close (); }    }}

　　

Common errors with Android SQLite