android - SQLLITEDATABASE crash-oncreate not called ? db.getreadabledatabase/getwritabledatabase crash -

i'm beginner @ android , sqlite well. have been trying build database retrieves , shows entries items, price , time. have looked through other topics can't seem find why crashes. have tried lot of ways make work, code trying use:

public class data extends sqliteopenhelper {     private static final string database_name ="items.db";     private static final string t="database created";     private static final int database_version=1;     context ct;     sqlitedatabase db;     public data (context ctx) {         super(ctx, database_name, null, database_version);         ct=ctx;      }      @override     public void oncreate(sqlitedatabase db) {         db.execsql("create table  record (_id primary key autoincrement,time text,item text,type text,amt text)");         int duration = toast.length_long;         toast toast = toast.maketext(ct, t, duration);         toast.show();     }      @override     public void onupgrade(sqlitedatabase db,int oldversion,int newversion) {         db.execsql("drop table if exists"+table_name);         oncreate(db);     }  } 

here class use run data class object

public class mainscreen extends activity {     private data data;     private static string[] cols={"_id","time","item","type","amt"};     private static string order_by = time + "desc";     private static int[] to={r.id.textview5,r.id.textview3,r.id.textview,r.id.textview4,r.id.textview2};      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.mainscreen);         data = new data(this);      }      public void tryit(view view)     {         time t=new time();         data test =new data(this);         add(t.tostring(),"tomato", "200", "food");          // cursor cursor = getd();         // show(cursor);     }       private void add(string t,string item, string price,string type) {         sqlitedatabase db = data.getwritabledatabase();         db.execsql("insert "+table_name+" values(null,'" + t + "','" + item + "','" + type + "','" + price + "')");     } } 

as of i'm trying database show entries add using add();

1. it not seem run oncreate @ data class (i used toast try , see if oncreate runs @ all)
2. trying use sqllitedatabase object getreadabledatabase/getwritabledatabase causes crash
3. even simple execsql("create******") method above causing crash.
4. the worst part worked 2-3 times yesterday. showed me 5-8 entries using listview wanted, , crashing sob.

i cant seem find problem!

i'm not sure how stackdump/trace if needed please tell me how it. have marked out cursor/adapters there no point getting work if database doesn't work.

i use tryit() button start insert...and crashes @

sqlitedatabase db = data.getwritabledatabase(); 

i think whole problem because reason database not getting created, using plain db.execsql statement whether in oncreate or using db object in data class , execsql @ constructor crashes app.

your create statement wrong, need add integer type _id, try this:

create table  record (_id integer primary key autoincrement,time text,item text,type text,amt text) 

more: https://www.sqlite.org/autoinc.html