android - Emulator stops responding, tables not created -

the application starts , database created. application stops responding when table created. error message: table magazine has no column named key_m_name. here code helper:

import com.example.projectdbms.model.magazine;  import android.content.contentvalues; import android.content.context; import android.database.sqlite.sqlitedatabase; import android.database.sqlite.sqliteopenhelper;  public class helper extends sqliteopenhelper {      // logcat tag     private static final string log = "helper";      // database version     private static final int database_version = 1;      // database name     private static final string database_name = "magazine publishers db";      // table names     private static final string table_magazine = "magazine";     private static final string table_article = "article";     private static final string table_editor = "editor";     private static final string table_author = "author";     private static final string table_category = "category";     private static final string table_distributor = "distributor";     private static final string table_advertisement = "advertisement";      // common column names       //distributor table - column names     private static final string key_d_no = "d_no";     private static final string key_dname = "name";     private static final string key_city = "city";     private static final string key_sales = "sales";      //author table - column names     private static final string key_a_id = "a_id";     private static final string key_a_name = "name";     private static final string key_a_dob = "d.o.b.";     private static final string key_a_sex = "sex";     private static final string key_a_articles = "no of articles";      //editor table - column names     private static final string key_e_id = "e_id";     private static final string key_e_name = "name";     private static final string key_e_dob = "d.o.b.";     private static final string key_e_sex = "sex";     private static final string key_e_articles = "no of articles";      //article table - column names     private static final string key_ar_no = "ar_id";     private static final string key_ar_date = "date";     private static final string key_ar_title = "title";      //magazine table - column names     private static final string key_m_name = "name";     private static final string key_edition = "edition";     private static final string key_m_date = "date";     private static final string key_pages = "pages";     private static final string key_price = "price";      //advertisement table - column names     private static final string key_pname = "product/service";     private static final string key_brand = "brand";     private static final string key_size = "size";      //category table - column names     private static final string key_cname = "category";     private static final string key_c_articles = "no of articles";      //table create statements      //magazine table create statement     private static final string create_table_magazine = "create table "      + table_magazine + "(" + key_m_name + " text not null, " + key_edition      + " integer, " + key_m_date + " integer," + key_pages + " integer not null, "      + key_price + " real, primary key(key_m_name, key_m_date))";      //editor table           private static final string create_table_editor = "create table "     + table_editor + "(" + key_e_id + " integer not null, " + key_e_name + " text not null,"      + key_e_dob + " integer, " + key_e_sex + " text," + key_e_articles      + " integer, primary key(key_e_id))";      //author table     private static final string create_table_author = "create table "     + table_author + "(" + key_a_id + " integer not null, " + key_a_name + " text not null, "      + key_a_dob + " integer, " + key_a_sex + " text," + key_a_articles     + " integer, primary key(key_a_id))";         //articles table      private static final string create_table_article = "create table "     + table_article + "(" + key_ar_no + " integer not null, " + key_ar_date     + " integer," + key_ar_title + " text not null, " + key_a_id + " integer, "      + key_e_id + "integer, primary key(key_ar_no)"      + "foreign key (a_id) references author(a_id) on delete cascade on update cascade," +      "foreign key (e_id) references editor(e_id) on delete cascade on update cascade)";      //category table                                  private static final string create_table_category = "create table "     + table_category + "(" + key_cname + " text not null," + key_c_articles     + " integer, primary key(key_cname))";        //advertisement table     private static final string create_table_advertisement = "create table "      + table_advertisement + "(" + key_pname + " text not null, " + key_brand      + " text not null, " + key_size + " integer, primary key(key_pname,key_brand))";      //distributor table     private static final string create_table_distibutor = "create table "      + table_distributor + "(" + key_d_no + " integer not null, " + key_dname      + " text not null, " + key_city + " text, " + key_sales + " integer, primary key(key_d_no))";          public helper(context context)     {         super(context, database_name, null, database_version);         //(context context, string name, sqlitedatabase.cursorfactory factory, int version)     }      @override     public void oncreate(sqlitedatabase db)     {         // creating required tables         db.execsql(create_table_magazine);         /*db.execsql(create_table_editor);         db.execsql(create_table_author);         db.execsql(create_table_article);         db.execsql(create_table_category);         db.execsql(create_table_advertisement);         db.execsql(create_table_distibutor);*/         //ins(db);     }      public void addmagazine(magazine magazine) {         sqlitedatabase db = this.getwritabledatabase();          contentvalues values = new contentvalues();         values.put(key_m_name, magazine.gettitle());         values.put(key_edition, magazine.getedition());          values.put(key_m_date, magazine.getdate());         values.put(key_pages, magazine.getpages());          values.put(key_price, magazine.getprice());         // inserting row         db.insert(table_magazine, null, values);         db.close(); // closing database connection     }      public void ins(sqlitedatabase db)     {         db.execsql("insert " + table_magazine + " values('times now',12,030112,45,40.50)");         db.execsql("insert " + table_magazine + " values('times finance',3,220410,52,50.00)");         db.execsql("insert " + table_author + " values(007,'ashwin m',040594,m,15)");         db.execsql("insert " + table_author + " values(002,'shino aburame',221296,m,4)");         db.execsql("insert " + table_author + " values(004,'percy shelley',210684,f,50)");         db.execsql("insert " + table_editor + " values(001,'lady tsunade',140883,f,10)");         db.execsql("insert " + table_editor + " values(005,'akshay k',150980,m,2)");         db.execsql("insert " + table_editor + " values(101,'o henry',181165,m,25)");         db.execsql("insert " + table_article + " values(003,220414,'endangered insects',002,001)");         db.execsql("insert " + table_article + " values(104,280390,'ode west wind',004,101)");         db.execsql("insert " + table_article + " values(81,140210,'road stardom',007,005)");         db.execsql("insert " + table_article + " values(81,140210,'hidden leaf village',002,001)");         db.execsql("insert " + table_category + " values('lifestyle',12)");         db.execsql("insert " + table_category + " values('news',14)");         db.execsql("insert " + table_category + " values('entertainment',21)");         db.execsql("insert " + table_category + " values('education',4)");         db.execsql("insert " + table_advertisement + " values('washing machine','ifb',5)");         db.execsql("insert " + table_advertisement + " values('3 bhk condo','prestige',11)");         db.execsql("insert " + table_advertisement + " values('r8 lemans','audi',8)");         db.execsql("insert " + table_distributor + " values(11,'advaith','bangalore',40)");         db.execsql("insert " + table_distributor + " values(05,'kakashi','tokyo',85)");         db.execsql("insert " + table_distributor + " values(03,'penguin','new york',120)");     }      @override     public void onupgrade(sqlitedatabase db, int oldversion, int newversion)     {         //on upgrade drop older tables         db.execsql("drop table if exists " + table_magazine);         db.execsql("drop table if exists " + table_article);         db.execsql("drop table if exists " + table_editor);         db.execsql("drop table if exists " + table_author);         db.execsql("drop table if exists " + table_category);         db.execsql("drop table if exists " + table_distributor);         db.execsql("drop table if exists " + table_advertisement);          //create new tables         oncreate(db);     } } 

you need pull variable names holding column names out of string literals in primary key declaration.

change this:

private static final string create_table_magazine = "create table "  + table_magazine + "(" + key_m_name + " text not null, " + key_edition  + " integer, " + key_m_date + " integer," + key_pages + " integer not null, "  + key_price + " real, primary key(key_m_name, key_m_date))"; 

to

private static final string create_table_magazine = "create table "  + table_magazine + "(" + key_m_name + " text not null, " + key_edition  + " integer, " + key_m_date + " integer," + key_pages + " integer not null, "  + key_price + " real, primary key(" + key_m_name + "," +  key_m_date + "))"; 

there similar problems in other tables, too, though code runs sql has been commented out now.