Add, delete, modify, and query SQLite instances (2)

Using the crud method that comes with SQLite to operate the database is not in favor of use, because the efficiency is not high to directly operate the SQL statement

So I only paste the example

Otherpersonservice

 Package  Com. tjp. Service;

  Import  Java. util. arraylist;
  Import  Java. util. List;

  Import  Android. content. contentvalues;
  Import  Android. content. context;
  Import Android. database. cursor;
  Import  Android. database. SQLite. sqlitedatabase;

  Import  Com. tjp. model. person;

  Public     Class  Otherpersonservice {

  Private  Dbopenhelp openhelp  =  Null  ;
  Private Context context;


  Public  Otherpersonservice (context ){
  This  . Context  =  Context;
Openhelp  =  New  Dbopenhelp (context );
}

  Public     Void  Save (person ){
Sqlitedatabase  = Openhelp. getwritabledatabase ();  //  The data needs to be changed. This method enables the database to be read and written with the cache function.
  //  Database.exe csql ("insert into person (name) values (?) ", New object [] {person. getname ()});  
  Contentvalues values  =  New  Contentvalues ();
Values. Put (  "  Name  "  , Person. getname ());
Database. insert ( "  Person  "  ,  Null  , Values );  //  Whether there is any data, you want to save the data in the database,
  //  Database. insert ("person", "name", null );  //  If no third field is specified or the number of the third parameter is 0, you must specify a null field.  
  }

  Public    Void  Update (person ){
Sqlitedatabase  =  Openhelp. getwritabledatabase ();
  //  Database.exe csql ("Update person set name =? Where personid =? ", New object [] {person. getname (), person. getpersonid ()});  
  Contentvalues values  =  New  Contentvalues ();
Values. Put (  "  Name "  , Person. getname ());
Database. Update (  "  Person  "  , Values,  "  Personid =?  "  ,  New  String [] {string. valueof (person. getpersonid ())});
}

  Public     Void  Delete ( Int  Personid ){
Sqlitedatabase  =  Openhelp. getwritabledatabase ();
  //  Database.exe csql ("delete from person where personid =? ", New object [] {personid });  
  Database. Delete (  "  Person  "  ,  "  Personid =?  " ,  New  String [] {string. valueof (personid )});
}

  Public  Person find (  Int  Personid ){
Sqlitedatabase  =  Openhelp. getwritabledatabase ();
Person  =  Null  ;
  // Cursor cursor = database. rawquery ("select * From person where personid =? ", New string [] {string. valueof (personid). tostring ()});  
  Cursor cursor  =  Database. Query (  "  Person  "  ,  New  String [] {  "  Personid  "  , "  Name  "  },
  "  Personid =?  "  ,  New  String [] {string. valueof (personid )},  Null  ,  Null  ,  Null  );
  If (Cursor. movetofirst ()){  //  If the movement is successful, it indicates the operation exists.  
    Int  Personida  =  Cursor. getint (cursor. getcolumnindex (  "  Personid  "  ));
String name  =  Cursor. getstring (cursor. getcolumnindex ( "  Name  "  ));
Person  =  New  Person (personida, name );
}
Cursor. Close ();
  Return  Person;
}

  Public  List  <  Person  >  Getscrolldate (  Int Offerset,  Int  Maxresult ){
List  <  Person  >  Persons  =  New  Arraylist  <  Person  >  ();
Sqlitedatabase  =  Openhelp. getwritabledatabase ();
 //  String SQL = "select * From person limit ?,? ";
  //  Cursor cursor = database. rawquery (SQL, new string [] {string. valueof (offerset), String. valueof (maxresult )});  
  
Cursor cursor  =  Database. Query (  "  Person  "  ,  Null  ,  Null ,  Null  ,  Null  ,  Null  ,  Null  , Offerset  +  "  ,  "  +  Maxresult );
  While  (Cursor. movetonext ()){
 Int  Personida  =  Cursor. getint (cursor. getcolumnindex (  "  Personid  "  ));
String name  =  Cursor. getstring (cursor. getcolumnindex (  "  Name  "  ));
Person  =  New Person (personida, name );
Persons. Add (person );
}
  Return  Persons;
}

  Public     Long  Getcount (){
Sqlitedatabase  =  Openhelp. getwritabledatabase ();
  //  Cursor cursor = database. rawquery ("select count (*) from person", null );  
  Cursor cursor =  Database. Query (  "  Person  "  ,  New  String [] {  "  Count (*)  "  },  Null  ,  Null  ,  Null  , Null  ,  Null  );
Cursor. movetofirst ();
  Int  Count  =  Cursor. getint (  0  );
Cursor. Close ();
  Return  Count;
}
} 

When the database is updated, the onupgrade command is executed as long as the version number is updated.